CHAPTER I.

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Transcriber's note:

There is an error in the calculation on page 16 (in the

paragraph beginning, "Hence, it is through the movement of

the mirror that the time, which is necessary for electricity

to go through the circuit of the wire . . ."). I have left

the calculation as it was printed.

Inconsistent hyphenation has been left as printed.

POPULAR BOOKS ON NATURAL SCIENCE.

For Practical Use in Every Household,

For Readers of All Classes.

by

A. BERNSTEIN.

_CONTENTS:_

THE WEIGHT OF THE EARTH--VELOCITY--NUTRITION--LIGHT

AND DISTANCE--THE WONDERS OF ASTRONOMY--METEOROLOGY--THE

FOOD PROPER FOR MAN.

New York:

Chr. Schmidt, Publisher, 39 Centre Street.

Entered, according to Act of Congress, in the year 1869, by

Chr. Schmidt,

In the Clerk's Office of the District Court of the United States, for

the Southern District of New York.

BERNSTEIN'S

POPULAR TREATISE

ON

NATURAL SCIENCE.

"In primis, hominis est propria VERI inquisitio atque investigatio.

Itaque cum sumus negotiis necessariis, curisque vacui, tum avemus

aliquid videre, audire, ac dicere, cognitionemque rerum, aut occultarum

aut admirabilium, ad bene beateque vivendum necessariam ducimus;--ex quo

intelligitur, quod VERUM, simplex, sincerumqe sit, id esse naturae

hominis aptissimum. Huic veri videndi cupiditati adjuncta est appetitio

quaedam principatus, ut nemini parere animus bene a natura, informatus

velit, nisi praecipienti, aut docenti, aut utilitatis causa juste et

legitime imperanti: ex quo animi magnitudo existit, et humanarum rerum

contemtio."

Cicero, de Officiis, Lib. 1. Sec. 13.

Before all other things, man is distinguished by his pursuit and

investigation of TRUTH. And hence, when free from needful business and

cares, we delight to see, to hear, and to communicate, and consider a

knowledge of many admirable and abstruse things necessary to the good

conduct and happiness of our lives: whence it is clear that whatsoever

is TRUE, simple, and direct, the same is most congenial to our nature as

men. Closely allied with this earnest longing to see and know the truth,

is a kind of dignified and princely sentiment which forbids a mind,

naturally well constituted, to submit its faculties to any but those who

announce it in precept or in doctrine, or to yield obedience to any

orders but such as are at once just, lawful, and founded on utility.

From this source spring greatness of mind and contempt of worldly

advantages and troubles.

CONTENTS.

PART I.

THE WEIGHT OF THE EARTH.

CHAPTER. PAGE.

I. How many pounds the whole earth weighs. 3

II. The attempt to weigh the earth. 5

III. Description of the experiment to weigh the earth. 8

PART II.

VELOCITY.

I. Velocities of the forces of nature. 13

II. How can the velocity of the electric current be ascertained. 15

PART III.

NUTRITION.

I. Nothing but milk. 21

II. Man the transformed food. 24

III. What strange food we eat. 26

IV. How nature prepares our food. 29

V. What becomes of the mother's milk after it has entered

the body of the child. 32

VI. How the blood becomes the vital part of the body. 35

VII. The circulation of matter. 38

VIII. Food. 41

IX. About nutrition. 44

PART IV.

LIGHT AND DISTANCE.

I. Something about illumination. 49

II. The illumination of the planets by the sun. 52

PART V.

THE WONDERS OF ASTRONOMY.

I. A wonderful discovery. 57

II. The main support of Leverrier's discovery. 60

III. The great discovery. 63

PART VI.

METEOROLOGY.

I. Something about the weather. 69

II. Of the weather in summer and winter. 73

III. The currents of air and the weather. 75

IV. The firm rules of meteorology. 78

V. Air and water in their relations to weather. 81

VI. Fog, clouds, rain, and snow. 84

VII. How heat in the air becomes latent, and how it gets free

again. 87

VIII. Latent heat produces cold, free heat produces warmth. 90

IX. Rules about the weather, and disturbances of the same. 93

X. The changeableness of the weather with regard to our

geographical position. 96

XI. About the difficulty and possibility of determining the

weather. 98

XII. The false-weather prophets. 101

XIII. Has the moon influence upon the weather? 103

PART VII.

OUR ARTICLES OF FOOD.

I. The rapid renewal of the blood is an advantage. 109

II. Digestion. 112

III. Coffee. 114

IV. Coffee as a medicine. 117

V. Usefulness and hurtfulness of coffee. 119

VI. Breakfast. 121

VII. Liquor. 125

VIII. Injuriousness of drinking liquor. 131

IX. The poor and the liquor. 134

X. The consequences of intemperance, and its prevention. 137

XI. Dinner. 140

XII. Necessity for variety in food. 143

XIII. Broth. 146

XIV. What is best to be put into soup. 149

XV. Leguminous vegetables. 152

XVI. Meat and vegetables. 155

XVII. The nap after dinner. 158

XVIII. Water and beer. 161

XIX. The supper. 164

PART I.

THE WEIGHT OF THE EARTH.

CHAPTER I.

HOW MANY POUNDS THE WHOLE EARTH WEIGHS.

Natural philosophers have considered and investigated subjects that

often appear to the unscientific man beyond the reach of human

intelligence. Among these subjects may be reckoned the question, "How

many pounds does the whole earth weigh?"

One would, indeed, believe that this is easy to answer. A person might

assign almost any weight, and be perfectly certain that nobody would run

after a scale, in order to examine, whether or not an ounce were

wanting. Yet this question is by no means a joke, and the answer to it

is by no means a guess; on the contrary, both are real scientific

results. The question in itself is as important a one, as the answer,

which we are able to give, is a correct one.

Knowing the size of our globe, one would think that there was no

difficulty in determining its weight. To do this, it would be necessary

only to make a little ball of earth that can be accurately weighed; then

we could easily calculate how many times the earth is larger than this

little ball; and by so doing, we might tell, at one's finger-ends,

that--if we suppose the little earth-ball to weigh a hundred-weight--the

whole globe, being so many times larger, must weigh so many

hundred-weights.

Such a proceeding, however, would be very likely to mislead us. For all

depends on the substance the little ball is made of. If made of loose

earth, it will weigh little; if stones are taken with it, it will weigh

more; while, if metals were put in, it would, according to the kind of

metal you take, weigh still more.

If, then, we wish to determine the weight of our globe by the weight of

that little ball, it is first necessary to know of what our globe

consists; whether it contains stones, metals, or things entirely

unknown; whether empty cavities, or whether, indeed, the whole earth is

nothing but a hollow sphere, on the surface of which we live, and in

whose inside there is possibly another world that might be reached by

boring through the thick shell.

With the exercise of a little thought, it will readily be seen that the

question, "How much does our earth weigh?" in reality directs us to the

investigation of the character of the earth's contents; this, however,

is a question of a scientific nature.

The problem was solved not very long ago. The result obtained was, that

the earth weighs 6,069,094,272 billions of tons; that, as a general

thing, it consists of a mass a little less heavy than iron; that towards

the surface it contains lighter materials; that towards the centre they

increase in density; and that, finally, the earth, though containing

many cavities near the surface, is itself not a hollow globe.

The way and manner in which they were able to investigate this

scientifically, we will attempt now to set forth as plainly and briefly

as it can possibly be done.

CHAPTER II.

THE ATTEMPT TO WEIGH THE EARTH.

It is our task to explain, by what means men have succeeded in weighing

the earth, and thus become acquainted with the weight of its

ingredients.

The means is simpler than might be thought at the moment. The execution,

however, is more difficult than one would at first suppose.

Ever since the great discovery of the immortal Newton, it has been known

that all celestial bodies attract one another, and that this attraction

is the greater, the greater the attracting body is. Not only such

celestial bodies as the sun, the earth, the moon, the planets, and the

fixed stars, but _all_ bodies have this power of attraction; and it

increases in direct proportion to the increase of the mass of the body.

In order to make this clear, let us illustrate it by an example. A pound

of iron attracts a small body near by; two pounds of iron attract it

precisely twice as much; in other words, the greater the weight of an

object, the greater the power of attraction it exercises on the objects

near by. Hence, if we know the attractive power of a body, we also know

its weight. Nay, we would be able to do without scales of any kind in

the world, if we were only able to measure accurately the attractive

power of every object. This, however, is not possible; for the earth is

so large a mass, and has consequently so great an attractive power, that

it draws down to itself all objects which we may wish other bodies to

attract. If, therefore, we wish to place a small ball in the

neighborhood of ever so large an iron-ball, for the purpose of having

the little one attracted by the large one, this little ball will, as

soon as we let it go, fall to the earth, because the attractive power of

the earth is many, very many times greater than that of the largest

iron-ball; so much greater is it, that the attraction of the iron-ball

is not even perceptible.

Physical science, however, has taught us to measure the earth's

attractive power very accurately, and this by a very simple instrument,

viz., a pendulum, such as is used in a clock standing against the wall.

If a pendulum in a state of rest--in which it is nearest to the

earth--is disturbed, it hastens back to this resting-point with a

certain velocity. But because it is started and cannot stop without the

application of force, it recedes from the earth on the other side. The

earth's attraction in the meanwhile draws it back, making it go the same

way over again. Thus it moves to and fro with a velocity which would

increase, if the earth's mass were to increase; and decrease, if the

earth's mass were to decrease. Since the velocity of a pendulum may be

measured very accurately by counting the number of vibrations it makes

in a day, we are able also to calculate accurately the attractive power

of the earth.

A few moments' consideration will make it clear to everybody, that the

precise weight of the earth can be known so soon as an apparatus is

contrived, by means of which a pendulum may be attracted by a certain

known mass, and thus be made to move to and fro. Let us suppose this

mass to be a ball of a hundred pounds, and placed near a pendulum. Then

as many times as this ball weighs less than the earth, so many times

more slowly will a pendulum be moved by the ball.

It was in this way that the experiment was made and the desired result

obtained. But it was not a very easy undertaking, and we wish,

therefore, to give our thinking readers in the next chapter a more

minute description of this interesting experiment, with which we shall

for the present conclude the subject.

CHAPTER III.

DESCRIPTION OF THE EXPERIMENT TO WEIGH THE EARTH.

Cavendish, an English physicist, made the first successful attempt to

determine the attractive power of large bodies. His first care was, to

render the attraction of the earth an inefficient element in his

experiment. He did it in the following way:

On the point of an upright needle he laid horizontally a fine steel bar,

which could turn to the right and left like the magnetic needle in a

compass-box. Then he fastened a small metallic ball on each end of the

steel bar. The balls were of the same weight, for this reason the steel

bar was attracted by the earth with the same force at both ends; it

therefore remained horizontal like the beam of a balance, when the same

weight is lying in each of the scales. By this the attractive force of

the earth was not suspended, it is true; but it was balanced by the

equality of the weights. Thus the earth's attractive power was rendered

ineffective for the disturbance of his apparatus.

Next he placed two large and very heavy metallic balls at the ends of

the steel bar, not, however, touching them. The attractive force of the

large balls began now to tell; it so attracted the small ones that they

were drawn quite near to the large balls. When, then, the observer, by a

gentle push, removed the small balls from their resting-place, the large

ones were seen to draw them back again. But as the latter could not stop

if once started, they crossed their resting-point, and began to vibrate

near the large balls in the same manner as a pendulum does, when acted

upon by the attractive force of the earth. Of course this force was

exceedingly small, compared with that of the earth; and for that reason

the vibrations of this pendulum were by far slower than those of a

common one. This could not be otherwise; and from the slowness of a

vibration, or from the small number of vibrations in a day, Cavendish

computed the real weight of the earth.

Such an experiment, however, is always connected with extraordinary

difficulties. The least expansion of the bar, or the unequal expansion

or contraction of the balls, caused by a change of temperature, would

vitiate the result; besides, the experiment must be made in a room

surrounded on all sides by masses equal in weight. Moreover, the

observer must not be stationed in the immediate neighborhood, lest this

might exercise attractive force, and by that a disturbance. Finally, the

air around must not be set in motion, lest it might derange the

pendulum; and lastly, it is necessary not only to determine the size and

weight of the balls, but also to obtain a form spherical to the utmost

perfection; and also to take care that the centre of gravity of the

balls be at the same time the centre of magnitude.

In order to remove all these difficulties, unusual precautions and

extraordinary expenses were necessary. Reich, a naturalist in Freiberg,

took infinite pains for the removal of these obstacles. To his

observations and computations we owe the result he transmitted to us,

viz.: that the mass total of the earth is nearly five and a half times

heavier than a ball of water of the same size; or, in scientific

language: The mean density of the earth is nearly five and a half times

that of water. Thence results the real weight of the earth as being

nearly fourteen quintillions of pounds. From this, again, it follows

that the matter of the earth grows denser the nearer the centre;

consequently it cannot be a hollow sphere.

If we consider, that from the earth's surface to its centre there is a

distance of 3,956 miles, and that, with all our excavations, no one has

yet penetrated even five miles, we have reason to be proud of

investigations which, at least in part, disclose to man the unexplorable

depths of the earth.

PART II.

VELOCITY.

CHAPTER I.

VELOCITIES OF THE FORCES OF NATURE.

In former times, when a man would speak of the rapidity with which light

traverses space, most of his hearers thought it to be a scientific

exaggeration or a myth. At present, however, when daily opportunity is

afforded to admire, for example, the velocity of the electric current in

the electro-magnetic telegraph, every one is well convinced of the fact,

that there are forces in nature which traverse space with almost

inconceivable velocity.

A wire a mile in length, if electrified at one end, becomes in the very

instant electrified also at the other end. This and similar things every

one may observe for himself; then, even the greatest sceptic among you

will clearly see, that the change--or "electric force"--which an

electrified wire undergoes at one end, is conveyed the length of a mile

in a twinkle, verily as if a mile were but an inch.

But we learn more yet from this observation. The velocity with which the

electric force travels is so great, that if a telegraph-wire, extending

from New York to St. Louis and back again, is electrified at one end,

the electric current will manifest itself at the other end in the same

moment. From this it follows, that the electric force travels with such

speed as to make a thousand miles in a space of time scarcely

perceptible. Or, in other words, it travels a thousand miles in the same

imperceptible fraction of a moment that it does a single mile.

And experience has taught us even more yet. However great the distance

connected by a telegraphic wire may be, the result has always been, that

the time which electricity needs to run that distance, is imperceptibly

small; so that it may well be said, its passage occupies an indivisible

moment of time.

One might even be led to believe that this is really no "running

through"--in other words, that this transmission of effect from one end

of the wire to the other end does not require any time at all, but that

it happens, as if by enchantment, in one and the same instant. This,

however, is not the case.

Ingenious experiments have been tried, to measure the velocity of the

elective force. It is now undoubtedly proved, that it actually does

require time for it to be transmitted from one place to another; that

this certain amount of time is imperceptible to us for this reason,

viz., that all distances which have ever been connected by telegraph,

are yet too small, to make the time it takes for the current to go from

one end to the other, perceptible to us.

Indeed, if our earth were surrounded by a wire, it would still be too

short for common observation, because the electric force would run even

through this space--twenty-five thousand miles very nearly--in the tenth

part of a second.

Ingenious experiments have shown that the electric current moves two

hundred and fifty thousand miles in a second. But how could this have

been ascertained? And are we certain that the result is trustworthy?

The measurements have been made with great exactitude. To those who are

not afraid of a little thinking, we will try to represent the way in

which this measurement was taken; although a perfect representation of

it is very difficult to give in a few words.

CHAPTER II.

HOW CAN THE VELOCITY OF THE ELECTRIC CURRENT BE ASCERTAINED.

In order to illustrate, how the velocity of the electric current can

actually be measured, we must first introduce the following:

Whenever a wire is to be magnetized by an electric machine, at the

moment it touches the machine, a bright spark is seen at the end of the

wire. The same spark is seen also at the other end of the wire, if

touching another apparatus. Let us call the first spark the

"entrance-spark," the other the "exit-spark." If a wire, many miles in

extent, is put up, and led back to where the beginning of the wire is,

both sparks may be seen by the same observer.

Now it is evident, that the exit-spark appears after the entrance-spark

just as much later, as the time it took the electric current to run from

one end of the wire to the other end. But in spite of all efforts made,

to see whether the exit-spark actually appears later, the human eye has

not been able to detect the difference. The cause of this is partly

owing to the long duration of the impression upon the retina, which

leads us to the belief, that we see objects much longer than we really

do; partly, the immense rapidity with which the exit-spark follows the

entrance-spark. From these two causes, we are tempted to believe both

sparks to appear at the same moment.

By an ingenious and excellent means, however, this defect in our eye has

been greatly diminished. It is well worth the trouble to read a

description of the experiment attentively. The truly remarkable way in

which it was tried, will please all who read it.

In order to measure the velocity of the electric current, the ends of a

very long wire are placed one above the other. If, now, one makes the

observation with the naked eye, both sparks will be found to stand in a

vertical line, one above the other, as the points of a colon, thus (:).

But he who wishes to measure the velocity of the electrical current does

not look upon the sparks with the naked eye, but into a small mirror,

which, by a clock-work, is made to revolve upon an upright axis with

exceedingly great rapidity. Thus he can see both sparks in the mirror.

If the apparatus be a good one, it will be observed that the sparks, as

seen by the aid of the mirror, do not stand in a vertical line above one

another, but obliquely, thus (.`).

Whence does this come?

The reason of it is, that after the appearance of the entrance-spark it

takes a short time, before the exit-spark appears. During this short

time the mirror moves, though but little, and in it the exit-spark is

seen as if it had moved aside from the entrance-spark.

Hence, it is through the movement of the mirror that the time, which is

necessary for electricity to go through the circuit of the wire, is

ascertained. A little reflection will readily convince the reader, that

the time may be precisely calculated, provided three things be known,

viz.: the length of the wire, the velocity of rotation of the mirror,

and the angular distance of the two sparks as seen in the mirror. Thus:

Suppose the wire to be 1,000 miles long; and suppose the mirror is made

to revolve 100,000 times in a second. Now, if the electrical current

traversed these 1,000 miles of wire during _one_ revolution of the

mirror, then it follows, that the current must move 1,000 miles in the

1/100 part of a second; or, 100,000 miles in a second.

It is found, however, that the mirror does not revolve an entire circle,

or 360 degrees, while the current is passing over 1,000 miles of wire,

but we find that the mirror turns through 144 degrees very nearly;

therefore the electric current must travel more than 100,000 miles a

second. How much more? Just as many times 100,000 miles, as 144 degrees

are contained in 360 degrees (the entire circle), viz., two and a half

times. Hence, the current travels 250,000 miles in a second.

PART III.

NUTRITION.

CHAPTER I.

NOTHING BUT MILK.

Conceive a man, gifted with the keenest intellect, but not knowing from

experience, that sucklings grow and become men, and imagine what he

would say, if you were to tell him this:

"Know, that the little being you see here, is a suckling, that is, a

developing human being, who by and by will become thicker and taller.

The bones of his body will become firmer and longer. The muscles that

animate these bones will likewise increase in size. The same will happen

with regard to his eyes, ears, nose, mouth; to his head, body, and feet;

every component part of his small body will be developed further and

further, until the child will become a perfect man."

There is no doubt, that he who does not know all this from experience,

will shake his head at it.

But if you were to tell him: "This development and growth have their

source in the baby's sucking at the mother's breast a white juice called

milk, and out of this milk all the constituent parts of the child are

manufactured within himself,"--certainly your hearer would laugh in your

face, and perhaps call you a credulous fool.

"What!" he would exclaim, "do you mean to say that milk contains flesh?

Or can you make bones out of milk, or hair? Can you make nails and teeth

out of milk? Do you wish to persuade me, that milk may be changed into

eyes? that from milk may be manufactured feet, hands, cheeks, eyelids,

and the various other parts of the human body?"

And if, in answer to this, you were to reply: "Yes, it is so. Within

this little creature is a factory, that not only makes all you have

mentioned, but much more. In this establishment, bones, hair, teeth,

nails, flesh, blood, veins, nerves, skin, juices, and water are

manufactured; all this is made from milk, and during the first months of

the child's life from nothing but milk,"--then your hearer, though he

may have the understanding of the most judicious of men, would be

dumbfounded, and would beseech you to tell him more about this factory.

You may be certain, he would like to know, how many boilers, cylinders,

valves, wires, ladles, oars, pumps, hooks, pins, spokes, and knobs there

may be in this factory; more especially would he wish to know, whether

the engine of this wonderful establishment be made of steel, wood,

cast-iron, silver or gold, or of diamonds.

Now, if you were to tell him, "It contains nothing of the kind. Of all

the factories you have seen in your life, there is none that bears any

resemblance to this one. And I will tell you furthermore, that it is not

even a complete factory, but it is continually developing; it becomes

larger and heavier like the child's body itself; moreover, the factory

does not consist of iron or steel, nor of gold or diamonds, but it

reproduces itself at every moment; it does so merely from the milk that

the child drinks,"--then, to be sure, your hearer would begin to doubt

his own senses; he would exclaim: "What is the intellect of the

intelligent, the judgment of the judicious, what is the wisdom of the

wise, when compared to a little of the mother's milk?"

And yet, you are well aware, my friendly reader, that mother's milk is,

after all, nothing but milk; and that milk, again, is nothing but a

means of nutrition; and nutrition, in its turn, is nothing but a part

of the action of the human body.

May I hope that you will favor me with your attention, while, in a few

articles, I speak to you about the nutrition of the human body?

CHAPTER II.

MAN THE TRANSFORMED FOOD.

Before speaking of the process of nutrition in the human body, we must

first obtain a correct idea of what is meant by nutrition.

Why are we obliged to eat?

Of course we know that hunger forces us to do so. But every one is aware

also, that above all we must ask, whence hunger arises; that we must

first get better acquainted with hunger itself, in order to understand

nutrition.

To explain this, however, it is necessary to turn our attention to

another thing, no less a miracle than nutrition itself, viz., what in

scientific language is called "Exchange of Matter." To all of you it is

a well-known fact, that nothing in the human body remains even for a

moment in the same state; but that in every part of the body a continued

exchange takes place. Air is breathed in and exhaled again; but the air

exhaled is different from the air inhaled. By this process an exchange

of matter has taken place; new matter has entered the body and waste

matter has been thrown out.

This exchange of matter--we shall speak more about it at another

opportunity--is a principal necessity for the body and its functions; it

consists in the main of an incessant change, by which our body is forced

to cast out matter that formed parts of it, and is therefore obliged, in

order to compensate for the loss, to take in new matter. Hence there is

no exaggeration in the expression, "Man is continually renewing

himself;" we indeed lose and receive particles of our body at every

moment. People have gone so far as to calculate that it takes seven

years for the renewal of the whole body of man, and that after this

space, there is not even an atom left of the man as he was seven years

before.

The regular exchange of matter, as we have seen, supposes the body to be

a barter-place, where people take in at the same ratio they pay out.

Since, however, man often pays out involuntarily and suffers so many

losses--by the mere process of breathing he ejects matter which he must

replace afterwards--this exchange of matter is the cause of the body's

possessing the feeling of want. The body has paid out and receives

nothing in return; this feeling of want is what we call "Hunger." It

forces us to absorb as much as we have paid out.

Nutrition, consequently, is the continual replacing of continual losses.

It is the wonderful transformation of food into the materials composing

the human body.

When looking at our fellow-men, however, we must not think, that they

are merely beings that have eaten food; but rather that they themselves,

viz., their skin, hair, bones, brain, flesh, blood, nails, and teeth,

are nothing but their own food, consumed and transformed.

CHAPTER III.

WHAT STRANGE FOOD WE EAT.

Man, according to what has preceded, is nothing but transformed food.

This idea may frighten us; it may be terrible to our hearts; but let us

frankly confess, it is a true one! Man consists only of such substances

as he has consumed; he is, in fact, nothing but the food he has eaten;

he is food in the shape of a living being.

A child is said to live on his mother's milk; but what else does this

mean than: "It is mother's milk, that has become alive by having been

changed into head, body, hands, feet, etc., etc."

Indeed, it may sound strange, yet it is quite correct: This mother's

milk in the shape of a human being consumes again new mother's milk,

and, by respiration, by evaporation and secretion of matter, casts out

the used-up milk.

This being so, it will now appear evident to every one, that by a

profound chemical knowledge of our daily food, we may readily learn to

know the chemical components of man, and _vice versa_; knowing the

substances of which man is made, it is easy for us to determine, what

kind of food he must take, in order to continually renew his body.

Since the mother's milk is the simplest and most natural food for the

child, let us consider it according to its importance. We shall then

have a stepping-stone towards the knowledge of the food of adults and

its effects. The mother's milk contains all the elements, with which

the human body can renew itself; should there be but one of those

elements wanting in it, the child would inevitably perish.

If, for example, milk did not contain calcareous earth, the consequence

would be, that the bones of the child would, soon after its birth,

neither grow nor increase in number, but they would fast diminish, and

the child would die in consequence of this. The attempt was once made to

feed animals on articles without calcareous parts, when, strange to

behold, they all grew fat, but very weak in their bones, and finally

broke down.

If milk contained no phosphorus, not only would the bones and teeth

suffer from the want of it, but even the completion of the child's brain

could not properly take place, and the child could not replace the

quantity of brain which it emits and loses every moment by breathing.

If there were no iron in the mother's milk, the child would die from the

green-sickness, a malady which, by the way, is dangerous also for grown

people, and which is cured by medicines containing plenty of iron.

If there were no sulphur in it, the child's bile could not develop; the

bile, as every one knows, has an important function in the human body.

These are but accessory elements of the mother's milk, elements which

usually are not looked upon as articles of food; for who is aware that

he must eat, and actually does eat daily, phosphorus, iron, calcareous

earth, and sulphur? And not only these; there are a great many other

articles, such as magnesia, chlorine, and fluor, that we eat without

being aware of it; moreover, our proper food consists also of three

gases: nitrogen, oxygen, and hydrogen; and of a solid substance called

"carbon," which is no less and no more than pure coal.

All these, my friendly readers, are contained in milk--all these are the

elements which in truth constitute the human body. Perhaps some persons

believe that there is nothing easier than to procure proper food. It

would only be necessary to take a certain quantity of carbon, hydrogen,

oxygen, and nitrogen; a little bit of potassium, natron, calcium, and

magnesia; to mix a small piece of iron, sulphur, phosphorus, chlorine,

and fluor, and take this mixture by the spoon at regular intervals, in

order to give the body the necessary aliments. This, however, would be a

mistake, for which the perpetrator would pay with his life.

Although it is true that these substances form the proper and most

important constituents of our daily food; yet, in order to enjoy the

desired result, we must not partake of them in their primary forms; they

can actually feed our body only when they are combined together in a

peculiar, wondrous manner.

In the next chapter it may be seen how nature first must combine these

substances before they are presented to us as proper food; and it will

also be seen, that we receive them sometimes in altogether different

forms and combinations; for example, in the mother's milk, when we eat

the above-named elements in the forms of caseine (cheese), butyrine

(butter), sugar of milk, salt, and water.

These latter names have a more savory sound, have they not?

CHAPTER IV.

HOW NATURE PREPARES OUR FOOD.

In the preceding article it was stated, that the food of the child which

lives on mother's milk, consists in its primary elements of peculiar

substances. These are principally oxygen, hydrogen, and nitrogen; three

gases to which may be added a large quantity of carbon, or, what is the

same, coal. Besides this wondrous mixture of air and coal, the mother's

milk contains still other elements, but in a smaller proportion. In

every-day life many of them are unfamiliar; for example, natron,

calcium, magnesia, chlorine, and fluor; the others, however, are known

to every one; viz., iron, sulphur, and phosphorus. All these strange

ingredients nature has carefully transformed into milk. For in their

primary state, and even in various chemical combinations that may be

produced artificially, they would be little adapted for the purpose. It

is therefore essentially necessary that nature herself should make them

ready for us. This she does by letting them pass first into the

vegetable state, and changing them afterwards into new forms.

The plant feeds on primary chemical elements; or, to state it more

correctly, the plant is nothing but transformed primary elements! Not

before the transformation of these elements into plants are the elements

adapted for food for animals and men.

Moreover, all that man eats must first have been in the vegetable state.

Now, it is true that man also eats the flesh, fat, and eggs of animals;

but whence have the animals meat and eggs? Only from the plants they

consume.

There is a remarkable succession of transformations in nature. The

primary elements nourish the plant; the plant nourishes the animal; and

both, plant and animal, form the nourishment of man.

Even the mother's milk, the simplest and most natural food of the child,

owes its existence only to the fact that the mother has eaten vegetable

and animal matter. This food, prepared for the mother by nature, has

been changed into the body of the same; and partly, also, it has become

the milk destined to nourish the child.

Hence it is evident that mother's milk consists of oxygen, nitrogen,

hydrogen, carbon, and a small portion of other chemical primary

elements. But these substances when appearing in the shape of milk, are

combined in such a manner as to form ready-made food; as such they

constitute, as stated above, caseine, butyrine, sugar of milk, salt, and

water.

The next questions are: "What do these elements of food perform when in

the child's body? What becomes of these substances after they have been

eaten by the child? How are they changed during the time of their stay

in the body? And in what condition do they leave the child's body, and

how do they force him to desire food again?"

These questions properly belong to the chapter on "Nutrition," where

they will be answered in their turn. Afterwards, we must be permitted to

turn our attention to a further question, viz., "What articles of food

are the most advantageous to man from the time he is weaned or the time,

he takes from among vegetable and animal matter the same substances for

food, that are contained in the mother's milk?"

In order to arrive at the answers to all these questions, we were

obliged to first prepare the ground a little. This was a gain on our

part, for now we shall attain the end in a shorter time than would have

been possible otherwise. We trust that we may give our reader a correct

idea of the subject, if he will but come to our aid with his most

earnest attention and reflection; these are needed here the more, as we

have to treat a difficult subject in a very short space.

CHAPTER V.

WHAT BECOMES OF THE MOTHER'S MILK AFTER IT HAS ENTERED THE BODY OF THE

CHILD?

When the child has freed itself from the body of its mother, it consists

of blood, flesh, and bones, which heretofore were formed and nourished

by the blood of the mother.

As soon, however, as the child is born, it ceases to be nourished in

this manner. It ceases, also, to secrete through its mother, substances

which are useless to it. The child now begins to breathe for itself, and

by its breath secretes carbon in the form of carbonic acid. Its skin

begins to perspire, and secretes chiefly hydrogen and oxygen in the

shape of water or vapor; by the urine, finally, it secretes nitrogen.

These substances--carbon, hydrogen, oxygen, nitrogen--before their

secretion, constituted vital parts of the child's body; now, however,

they are wasted, and for this reason must be thrown off.

It is evident that the child wants compensation for this loss. This is

given by the mother's milk; for it contains chiefly these same

substances.

But how is this effected?

The milk passes from the child's mouth through the gullet into the

stomach. While yet in the mouth, the milk is mixed with a certain liquid

called saliva. This saliva possesses the quality of preparing the milk

for the necessary change which will take place, when it reaches the

child's stomach. The principal work, however, is carried on in the

stomach itself. Its sides secrete a liquid called "gastric juice,"

whose business it is, to transform into a pulp milk, and also solid

food, provided the latter be well masticated and moistened.

Science has taught us to prepare gastric juice artificially. The process

of digestion, that is, the transformation of solid food--the crust of

bread, meat, etc.--into a pulp, may nowadays be observed in a glass

filled with warm, artificial, gastric juice.

After the digestion is completed, the lower opening of the stomach,

which leads into the duodenum, and which, during the process of

digestion, was closed by a muscle, opens itself. The pulp, now called

"chyme," flows into the continuation of the stomach--the "alimentary

canal" or "duodenum." This is but a long bag with many folds and

windings.

The chyme is here mixed again with a liquid called "intestinal juice;"

it has the quality of continuing digestion until the chyme separates

into two parts; one of them, a milky fluid called "chyle," contains the

substance which feeds the body. The other is the solid parts not adapted

to nutrition; they are thrown out by the lower opening of the "rectum."

But how is this nutritive part, the chyle, conveyed into the various

parts of the body?

The intestinal canal is filled with extremely small vessels called

"lacteal absorbents." These vessels absorb the chyle. This absorption,

on account of the great length of the intestinal canal--in adults it is

nearly thirty feet long--is, in a healthy body, accomplished very

thoroughly. The real nutriment for the body is now contained in the

lacteal absorbents, an infinite number of small tubes.

All these small vessels, however, converge towards the lower part of the

spinal column, and uniting, form a vessel which ascends into the chest;

here it empties into a large blood-vessel, the blood of which is on its

way to the heart. Thrown out of the heart in another direction, the

blood is pushed through the whole body.

Thus the food, after having been transformed into a juice very similar

to the blood, joins the blood after a circuitous journey, and is finally

mixed with, or, more properly, changed into, blood.

CHAPTER VI.

HOW THE BLOOD BECOMES THE VITAL PART OF THE BODY.

One would be well justified in calling the blood "man's body in a liquid

state." For the blood is destined to become the living solid body of

man.

People were astonished, when Liebig, the great naturalist, called blood

the "liquid flesh;" we are correct even in going further and calling the

blood "man's body in a liquid state." From blood are prepared not only

muscles and flesh, but also bones, brain, fat, teeth, eyes, veins,

cartilages, nerves, tendons, and even hair.

It is utterly wrong for anybody to suppose, that the constituents of all

these parts are dissolved in the blood, say as sugar is dissolved in

water. By no means. Water is something quite different from the sugar

dissolved in it; while the blood is itself the material from which all

the solid parts of the body are formed.

The blood is received into the heart, and the heart, like a pump, forces

it into the lungs. There it absorbs in a remarkable manner the oxygen of

the air which comes into the lungs by breathing. This blood, saturated

now with oxygen, is then recalled to another part of the heart by an

expansive movement of that organ.

This part of the heart contracts again and impels the oxygenated blood

into the whole body by means of arteries, which branch out more and

more, and become smaller and smaller, until at last they are no longer

visible to the naked eye. In this manner the blood penetrates all parts

of the body, and returns to the heart by means of similar thread-like

veins, which gradually join and form larger veins. Having reached the

heart, it is again forced into the lungs, and absorbs there more oxygen,

returns to the heart, and is again circulated through the whole system.

During this double circulation of the blood from the heart to the lungs

and back, and then from the heart to all parts of the body and back

again--during all this, the change of particles, so remarkable in

itself, is constantly going on: the exchange by which the useless and

wasted matter are secreted and new substances distributed. This fact is

wonderful, and its cause not yet fully explained by science; but so much

is certain, that the blood when being conveyed to all parts of the human

body, deposits whatever at the time may be needed there for the renewal

of that part.

Thus the blood that has been formed in the child from the mother's milk,

contains phosphorus, oxygen, and calcium. These substances, during the

circulation of the blood, are deposited in the bones, and form

"phosphate of lime," the principal element in the bone. In the same

manner fluor and calcium are given to the teeth. The muscles, or flesh,

also receive their ingredients from the blood; so do the nerves, veins,

membranes, brain, and nails; also the inner organs, such as the heart,

lungs, liver, kidneys, intestines, and stomach.

They all, however, in return give to the blood their waste particles,

which it carries to that part of the human body where they may be

secreted.

If any member of the body is so bound, that the blood cannot circulate,

it must decay; for the life of the body consists in its constant change

and transformation, in the continual exchange of fresh substances for

waste ones. But this vital exchange is only kept up by the constant

circulation of the blood, which, while it decreases by being

transformed into vital parts of the body, is always formed anew by our

daily food.

Food is therefore very justly called "Means of Existence," and the blood

may rightly be called the "Juice of Life."

CHAPTER VII.

CIRCULATION OF MATTER.

Thus we have seen that the human body is vital blood, transformed and

solidified. Now, blood is food transformed; food consists of primary

elements prepared and changed by nature; hence, man himself is primary

matter transformed and vivified.

But the human race being thousands and thousands of years old, and there

being upon the earth besides man the whole of the animal kingdom,

developing, preserving, and nourishing itself bodily like man; the

question arises: Whence do they all come, these primary elements that

are obliged forever to undergo transformation before they can become

animated vital matter? Do these primary elements not incessantly

decrease during the long process of their being changed into plants and

consumed by man and animal, in order to form human and animal bodies

afterwards?

The answer to this interesting question has been given already. The

human body is not framed or created anew at every moment by food; but it

is at every moment, that small particles of the human body die. These

particles are returned to mother earth from which they sprang, thus

going back to the primary elements.

It is not only those who are dead, that render to the earth what belongs

to her, that return to nature what she gave them; but in a far greater

degree it is the living, that pay their debt to nature.

Man's body is not his own; nature has lent it to him but for a short

term of service; then nature wrests her loan back from him. Thus must

man, spite all his pride, accept her never-ceasing offer; daily he must

borrow and daily he must repay in part, until the moment comes when he

borrows for the last time, the moment he expires; and dying he leaves it

to those around his bedside, to pay his last debt to earth.

Is it not wonderful? His own blood is the messenger that daily carries

new loans to him, and, in the shape of transformed food, of transformed

elements of nature, equips his body. But his own blood is at the same

time also his cashier, who, having rendered him service, takes the loan

away, by secreting from the body elements that are thus returned to

nature.

With every revolution of the blood the body is supplied with transformed

food, which is immediately changed into vital parts of the body; with

every return of the blood waste matter is carried off and deposited,

where it may be thrown out.

The blood carries waste matter to the kidneys that they may send out of

the body, in the shape of urine, waste nitrogen, mixed with a part of

the phosphate of lime, that served to form bones and teeth, but is now

useless. The blood, besides, secretes perspiration through the skin.

This is a liquid containing water, hence oxygen and hydrogen; but is

moreover mixed with various other waste substances of the body, as for

example, carbonic acid, nitrogen and fat. Chiefly, however, the blood is

employed in carrying waste carbon to the lungs, so that they may, by the

process of respiration, exhale carbonic acid, a gas which would prove of

deadly effect if remaining in the lungs too long, or if inhaled.

The quantity of man's secretion per day is by no means small. It amounts

to the fourteenth part of his own weight: nay, more--the weight of his

perspiration alone, secreted partly by evaporation in the shape of gas,

partly as a liquid in drops, amounts during twenty-four hours to nearly

two pounds.

Secreted substances have lost all the qualities of transformed and vital

matter. They return to the primary elements and serve as food

principally to plants, which before had offered those very same

substances as food to man.

It is in this manner that the great circulation of matter in nature

takes place. From the lifeless primary elements to the plant; from the

plant, in the shape of food, to animal and man; from these, as waste

substances, back again to the primary elements, there to begin anew a

circulation, by means of which inanimate elements are reanimated, and

vital elements made lifeless again; that is, life changed again into

death.

And it is in this circulation that our "Nutrition," or, more precisely,

the "Change of Matter in Man," consists, an important link in the

life-preserving chain of nature.

CHAPTER VIII.

FOOD.

From what has been said, it must appear evident that only such dishes

make good food as contain the same constituents as the blood.

To have these constituents, food must contain salt, fat, and sugar; all

these ingredients must, of course, be in a certain proportion.

That water is essential for the support and renewal of the body is clear

to every one. The flesh we eat, contains nearly eighty per cent. of

water, and yet a man must die, if he were to eat nothing but meat and to

have no water, for the reason that the eighty per cent. of water he

takes in would by no means be sufficient to form all the liquids

necessary for the human body.

The albumen that we eat, forms in the blood chiefly the substances

composing the muscular part of the flesh. But it is an error to suppose,

that therefore it is absolutely necessary to eat eggs--the white of an

egg is nearly pure albumen--because the caseine (cheese) contains

precisely the same ingredients as the albumen; for we have seen before,

and our readers are doubtless aware of it, that the mother's milk

contains caseine, while it is entirely free of albumen. Hence, he who

eats plenty of caseine, as do shepherds in Switzerland, for example,

scarcely needs any meat. But besides caseine there is another element,

viz., the vegetable albumen called gluten, which contains albuminous

matter; so do all glutinous plants. Peas, beans, and lentils in

particular form food productive of flesh.

The salts that must be given to the blood, do not only consist in the

common kitchen-salt. By the expression "Salts" are meant various

combinations of substances which are usually not considered articles of

food, for example, the combinations of phosphorus, iron, etc., but are

not visible to the eye. They help to form bones, teeth, nails,

cartilages, and hair.

The fat which we take, appears to many people to be a very important

part of our food, and they believe that by eating much fat, one may

become fat. But this is not correct. Ferocious animals that live only on

meat and fat, do not get fat; while herbivorous animals fatten

excessively, if provided with good mast, consisting of course but of

plants. Yet fat is, for all this, by no means superfluous to our body.

Man needs it, because it is the fat which chiefly supports his

respiration. But the fat that is needed for the body, is formed by man

himself; so that but little of it need be eaten, and that little only

for the purpose of helping to form new fat from sugar.

It is therefore best to consider fat and sugar as food belonging

together; for the fat is formed in the body from sugar, and the small

quantity of fat which we take daily is only to promote the

transformation of sugar into fat.

But let no one believe that one must needs actually eat sugar; no, every

food that contains starch supplies the place of sugar very well, as

starch is changed, when in the body, first to sugar and then to fat. The

potato contains starch and serves its purpose well; it is necessary,

however, to put butter with it in order that the starch and sugar formed

from the potato in the stomach, may be easily converted into fat.

An excellent article of food is bread, for it contains nearly all the

elements of nutrition. It contains vegetable albumen, and therefore is

converted into flesh. It has nearly all the salts that are essential to

the body; moreover, it contains starch from which fat is produced.

Therefore, by the mere addition of a little butter in order to make the

formation of fat easier, and by drinking water besides, the human body

is able to exist. On the other hand, the potato, if taken alone, is an

insufficient means of nutrition. Neither would meat or albumen, if taken

alone, be able to preserve life.

Various experiments have been tried with animals, and a great deal of

information about the best means of feeding the body has been collected.

In order to investigate the effect of the nutritive qualities of food,

inquiries have been made especially at military establishments, such as

barracks, etc.

CHAPTER IX.

ABOUT NOURISHMENT.

In obedience to the demands of modern science, numerous experiments

about nutrition have been made, in regard to digestion as well as to the

effects of hunger and of various elements of food.

As to digestion, the most excellent observations were made on men

afflicted with a fistula in the abdomen, that is, a wound penetrating to

the stomach. By means of this wound, it was ascertained very minutely

how long it took to digest food, and what kind of transformation it

underwent. From this and other experiments it appeared, that the time

for digestion, though varying greatly with the various articles of food,

lasts from one and one-half to five and one-half hours. Those most

quickly digested are: soft sweet apples, beaten eggs, and cooked brain.

To digest boiled milk, raw eggs, soft sour apples, roasted beef, liver,

two hours were required. Cooked spinal marrow, raw cabbage, fresh milk,

roasted beef, oysters, soft-boiled eggs, and raw ham, took nearly three

hours. Wheat bread, old cheese, potatoes were digested in nearly three

and one-half hours; pork, boiled cabbage, lamb's fat, not before five

hours.

The experiments about the effects produced by hunger were tried only on

animals. The results were that during the state of starvation

three-fourths of the blood disappeared; the fat was almost entirely

consumed; the flesh disappeared one-half; even the skin diminished

one-third, and the bones lost about one-sixth of their weight. The

least decrease was found to be in the nerves, a striking proof that

nerves possess a great power of self-preservation, provided there be but

a minimum of matter to feed them. From numerous experiments the

conclusion was drawn, that an adult weighing about one hundred and

thirty pounds must die if he were to lose, say fifty pounds, by

starvation.

With regard to the effects of the various articles of food, experiments

applied to dogs have shown that they can live on bones for a long time;

but that they die if fed on sugar only, and when examined after death,

no trace of any fat is to be found.

Animals fed on substances that contained no phosphorus and lime became

fat; but they died for want of the proper nourishment for their bones.

Animals died also when nourished only with pure albumen or pure caseine.

The most remarkable fact in this connection is, that they perished in

the same length of time in which they would have died, _if they had

taken no food whatever_.

Experiments tried on man have shown that it is injurious to eat

_uniform_ food. A constant change in our food is extremely nourishing

and healthy. This is an experience made in prisons and barracks; changes

of food are made there every day during the week, so that each day they

have a different dinner. Once, a physician in England wished to try the

effects of uniform food on himself. He took nothing but bread and water

for forty-five days; in consequence of this he decreased eight pounds.

Then he ate for four weeks but bread and sugar, then bread and oil three

weeks; but finally he succumbed under his experiments, and died, after

having experimented thus for eight months.

We must not, therefore, call it daintiness when we feel an appetite for

more variety of food, or if we soon get tired of uniform meals: a

constant change in this respect is necessary. Experiments have shown

that rabbits continue their health, if alternately they receive one day

potatoes, the next day barley; but if they receive exclusively potatoes

or barley, they soon die.

In conclusion, we will mention a few articles of food and their

qualities. Among grains, wheat is known to be the most nutritive, and

wheat bread and meat taken together is always good, wholesome food. Rice

produces fat, but if taken by itself, it is not worth much, since it is

nourishing only if eaten with butter, or fat, and a little meat. Potato

is a cheap, and yet an expensive food; for it contains very little

nutriment. In order to be of benefit it must be eaten in great quantity;

besides, it is necessary to season it with salt, butter, or fat, as

otherwise it would be totally useless. A good diet is peas, beans, and

lentils; but their hulls are indigestible, and must be removed.

In general, beverages are not counted among articles of food; and

kitchen-salt is commonly believed to be but a matter of taste; but this

is a great mistake. Coffee and tea, too, are nourishing in their way;

good beer is equal to half a dinner, and as to salt, a frequent relish

of the same is an excellent means of nutrition.

Cheap coffee, cheap beer, and cheap salt are therefore a great benefit

to the people.

PART IV.

LIGHT AND DISTANCE.

CHAPTER I.

SOMETHING ABOUT ILLUMINATION.

From time to time we hear of plans to illuminate whole cities by a great

light from a single point. The credulity of the newspaper public about

affairs belonging to Physics is so great, that we are not surprised if

such plans are spoken of as practicable; though, indeed, one needs but

cast a glance of reflection on them, to be at once convinced of their

impracticability.

The impracticability does not consist so much in this, that no such

intense light can be made artificially, as in the circumstance that the

illuminating power of light decreases enormously as we recede from it.

In order to explain this to our readers, let us suppose that on some

high point in New York city, say Trinity-church steeple, an intensely

brilliant light be placed, as bright as can be produced by gases or

electricity. We shall see, presently, how the remoter streets in New

York would be illuminated.

For the sake of clearness, let us imagine for a moment, that at a

square's distance from Trinity church there is a street, intersecting

Broadway at right angles. We will call it "A" street. At a square's

distance from "A" street let us imagine another street running parallel

to it, which we will call "B" street; and again, at a square's distance,

a street parallel to "B" street, called "C" street; thus let us imagine

seven streets in all--from "A" to "G"--running parallel, each at a

square's distance from the other, and intersecting Broadway at right

angles. Besides this, let us suppose there is a street called "X"

street, running parallel with Broadway and at a square's distance from

it; then we shall have seven squares, which are to be illuminated by one

great light.

It is well known that light decreases in intensity the further we recede

from it; but this intensity decreases in a peculiar proportion. In order

to understand this proportion we must pause a moment, for it is

something not easily comprehended. We hope, however, to present it in

such a shape, that the attentive reader will find no difficulty in

grasping a great law of nature, which, moreover, is of the greatest

moment for a multitude of cases.

Physics teach us, by calculation and experiments, the following:

If a light illuminates a certain space, its intensity at twice the

distance is not twice as feeble, but two times two, equal four times, as

feeble. At three times the distance it does not shine three times as

feeble, but three times three, that is nine times. In scientific

language this is expressed thus: "The intensity of light decreases in

the ratio of the square of the distance from its source."

Let us now try to apply this to our example.

We will take it for granted that the great light on Trinity steeple

shines so bright, that one is just able to read these pages at a

square's distance, viz., on "A" street.

On "B" street it will be much darker than on "A" street; it will be

precisely four times darker, because "B" street is twice the distance

from Trinity church, and 2 x 2 = 4. Hence, if we wish to read this on

"B" street, our letters must cover four times the space they do now.

"C" street is three times as far from the light as "A" street; hence it

will be nine times darker there, for 3 x 3 = 9. This page in order to be

readable there, would then have to cover nine times the space it

occupies now.

The next street, being four times as remote from the light as "A"

street, our letters, according to the rule given above, would have to

cover sixteen times the present space, for it is sixteen times darker

there than on "A" street.

"E" street, which lies at five times the distance from the light, will

be twenty-five times darker, for 5 x 5 = 25. "F" street, which is six

times the distance, we shall find thirty-six times darker; and, lastly,

"G" street, seven times the distance from the light, will be forty-nine

times darker than "A" street, because 7 x 7 = 49. The letters of a piece

of writing, in order to be legible there, must cover forty-nine times

the surface that our letters cover now.

But the reader will exclaim: "This evil can be remedied. We need but

place forty-nine lights on Trinity steeple; there will then be

sufficient light on "G" street for any newspaper to be read." Our friend

will easily perceive, however, that it is more judicious to distribute

forty-nine lights in different places on Broadway, than to put them all

on one spot.

This is sufficient to convince any one that we may be able to illuminate

large public places with _one_ light, but not the streets of a city, and

still less whole cities.

CHAPTER II.

ILLUMINATION OF THE PLANETS BY THE SUN.

It was demonstrated above, that it is impossible to illuminate large

distances by a single light. Yet we must acknowledge that nature herself

does this, and that the sun is the only light which shines throughout

the solar system; for the light which is seen in the planets is but

light received and reflected from the sun.

This is sufficient reason for us to believe, that there are not on every

planet creatures as we see them on our earth; but that, on the contrary,

each celestial body may be inhabited by creatures organized according to

the distance of the planet from the sun; that is, adapted to the degree

of light produced there by the sun.

For the natural sciences teach us, that solar light is subject to the

same laws as our artificial light: it decreases as the distance

increases. The planets more remote from the sun are illuminated less

than those nearer to it. The ratio in which this light decreases, is

precisely the same as that of the terrestrial light illustrated above,

viz., according to the square of the distance. In other words, when the

distance is double, the intensity of the light is one-fourth as great;

when three times, one-ninth as great; when four times more remote,

one-sixteenth as strong, etc.; in short, at every distance as much

weaker as the distance multiplied by itself.

Presently we shall see that the planets are illuminated in inverse

proportion to their distance from the sun. From this alone we come to

the conclusion, that on every planet the living beings must necessarily

be differently constituted.

The name of the planet nearest to the sun is Mercury. It is about two

and a half times nearer to the sun than our earth, therefore it receives

nearly seven times as much light. We can scarcely conceive such an

intensity of light and all the consequences resulting from it. If

instead of one sun we should happen to have three, there is no doubt

that we should go blind; but seven suns, that is, seven times the light

of our brightest days, we could not endure, even if our eyes were

closed; the more so, as our eyelids, even when firmly closed, do not

protect us from the sun's light entirely. This is a proof of our

assertion, that the living beings on the planet Mercury must be

differently organized from us.

Venus, the third planet, is one and a third times nearer to the sun than

we are. The light on that planet, therefore, is nearly twice as bright

as on ours. But inasmuch as even this would be unbearable for us, the

creatures on this planet must likewise be different from us.

The third planet is the earth we inhabit. The intensity of the sunlight

in bright summer days is well known to us from experience, although no

one has as yet been successful in measuring its degree as precisely as

has been done with heat by the thermometer. It is true that in modern

times a certain Mr. Schell, in Berlin, proposed to measure light

accurately, in a way that elicited the approbation of naturalists,

especially of Alexander von Humboldt. However, the experiments proposed

have not yet been properly carried out, though they are very useful to

photographists. Therefore we do not know, up to the present time,

whether there is any difference in the light of two cloudless summer

days; just as little are we able to determine how much the moon's light

is weaker than the sun's.

The fourth planet's name is Mars; its distance from the sun is one and

a half times our distance from the sun. There the sun's light is about

half as strong as with us. Now, although we often may have days which

are half as bright as others, it is yet very doubtful whether we could

live on Mars; for light does not act upon our eyes only, but on our

whole body and its health. It is likely that the very want of light

there would prove fatal to us.

The twenty-four newly discovered planets have days that are nearly six

times darker than ours. The daylight on these planets is probably as it

was with us during the great eclipse of the sun in July, 1851. This

light was very interesting for a few minutes, but if it were to continue

it would certainly make us melancholy.

Far worse yet fare the remoter planets. On the planet Jupiter it is as

much as thirty times darker than with us. On Saturn, eighty times. On

Uranus, even three hundred times; and upon the last of the planets,

Neptune, discovered in 1845, light is nine hundred times more feeble

than upon our globe.

Although it is true that all of the remoter planets have many moons or

satellites, yet it must not be forgotten that the moons themselves are

but very feebly illuminated; that their light benefits during the night

only, and even then only lovers and night revellers.

PART V.

THE WONDERS OF ASTRONOMY.

CHAPTER I.

A WONDERFUL DISCOVERY.

Many people are greatly surprised, that when a new planet is

discovered--and within late years this has been frequently the

case--astronomers should be able to determine a few days afterwards its

distance from the sun, together with the number of years necessary for

its orbit. "How is it possible," they ask, "to survey a new guest after

such a short acquaintance so accurately, as to foretell his path, nay,

even the time of his course?"

Nevertheless it is true that this can be done, and certainly no

stage-coach nor locomotive can announce the hour and minute of its

arrival with as much accuracy as the astronomer can foretell the arrival

of a celestial body, though he may have observed it but a short time.

More yet is done sometimes. In 1846, a naturalist in Paris, Leverrier by

name, found out, without looking in the sky, without making observations

with the telescope, simply by dint of calculation, that there must exist

a planet at a distance from us of 2,862 millions of miles; that this

planet takes 60,238 days and 11 hours to move round the sun; that it is

24 1/2 heavier than our earth, and that it must be found at a given time

at a given place in the sky; provided, of course, the quality of the

telescope be such as to enable it to be seen.

Leverrier communicated all this to the Academy of Sciences in Paris. The

Academy did not by any means say, "The man is insane; how can he know

what is going on 2,862 millions of miles from us; he does not even know

what kind of weather we shall have to-morrow!" Neither did they say,

"This man wishes to sport with us, for he maintains things that no one

can prove to be false!" Nor, "The man is a swindler, for he very likely

has seen the planet accidentally, and pretends now that he discovered it

by his learning." No, nothing of the kind; on the contrary, his

communication was received with the proper regard for its importance;

Leverrier was well known as a great naturalist.

Having thus learned how he made the discovery, the members of the

Academy felt convinced that there were good reasons to believe his

assertions to be true.

Complete success crowned his efforts.

He made the announcement to the Academy in January, 1846; on the 31st of

August he sent in further reports about the planet, which he had not

seen as yet. The surprise and astonishment on the part of scientific men

can scarcely be imagined, while on the part of the uneducated there were

but smiles and incredulity.

On the 23d of September, Mr. Galle--now Director of the Breslau

Observatory, at that time Assistant in that of Berlin, a gentleman who

had distinguished himself before by successful observations and

discoveries, received a letter from Leverrier, requesting him to watch

for the new planet at a place designated in the heavens. Though other

cities at that time possessed better telescopes than Berlin, this city

was chosen because of its favorable situation for observations.

That same evening Galle directed his telescope to that spot in the sky

indicated by Leverrier, and, at an exceedingly small distance from it,

actually discovered the planet.

This discovery of Leverrier is very justly called the greatest triumph

that ever crowned a scientific inquiry. Indeed, nothing of the kind had

ever transpired before; our century may well be proud of it. But, my

friendly reader, he who lives in this age without having any idea

whatever of the way in which such discoveries are made--he does not

deserve to be called a contemporary of this age.

We will not try to make an astronomer out of you; we merely wish to

explain to you the miracle of this discovery.

CHAPTER II.

MAIN SUPPORT OF LEVERRIER'S DISCOVERY.

When Leverrier was working at his great discovery he did not strike out

a new path in science; he was supported by a great law of nature, the

base of all astronomical knowledge. It is the law of gravitation,

discovered by Sir Isaac Newton.

Those of our readers who have fully understood what we said before (page

50) about light, will now easily comprehend, what we are going to say

about the force of gravity.

Every heavenly body is endowed with the power of attraction; that is, it

attracts every other body in the same manner that a magnet attracts

iron. If the celestial bodies, or, to speak only of one class, if all

the planets were at rest, that is, without motion, they would, on

account of the great attractive power of the sun, rapidly approach it,

and finally unite with it and form one body.

That this does not take place, may be ascribed solely to the fact that

all planets have their own motion. This motion, combined with the

attractive force of the sun, causes them to move in circles around it.

This may be illustrated by the following: Suppose a strong magnet to lie

in the centre of a table. Now, suppose some one to place an iron ball on

the table; then will this ball run straightway towards the magnet. But

if some one were to roll the ball so that it should pass the magnet, it

would at first run in a straight line, but the magnet attracting it at

every moment of time, the ball would be compelled to deviate from its

straight course and would begin to circulate round the magnet.

We see that this circular motion round the magnet springs from two

forces: first, from the hand that starts the ball in a straight line;

and secondly, from the attraction of the magnet, which at every moment

draws the ball towards itself.

Newton, the greatest natural philosopher of all times, who lived in

England two hundred years ago, proved, that all the orbits round the

sun, as described by the planets, are caused by two such forces; by the

motion of the planets peculiar to themselves, which, if not interfered

with, would make them fly through space in a straight line; and by the

attractive force of the sun, which is continually disturbing that

straight course, thus forcing the planets to move in circles around him.

But Newton has discovered more than this. He succeeded in proving that,

knowing the time of a planet's revolution around the sun, we can

determine precisely with what force the attractive power of the sun

affects it. For if the sun's attractive power is strong, the planet will

revolve very quickly; if weak, it will move slowly.

Were the sun, for example, all of a sudden to lose a portion of his

attractive force, the consequence would be that the earth must revolve

around him more slowly. Our year, which now has three hundred and

sixty-five days, would then have a much greater number of days.

Newton has also shown--and this is for us the main thing--that the

attractive force of the sun is strong in his close proximity, but that

it diminishes as the distance from him increases. In other words, the

remoter planets are attracted by the sun with less force than those

nearer to him. The attractive force decreases with the distance in the

same proportion as light, which, we saw a little while ago, decreases in

intensity as the square of the distance increases. This means, that a

planet at a distance from the sun twice as great as that of the earth,

is attracted with only one-fourth the force; one that is three times the

distance, with one-ninth of the force, etc.

This great law pervades all nature. It is the basis of the science of

astronomy, and was the main support of Leverrier's discovery.

CHAPTER III.

THE GREAT DISCOVERY.

Perhaps the question presents itself to the thinking reader: If it be

true that the heavenly bodies attract each other, why do not the planets

attract one another in such a manner that they will run round and about

each other?

Newton himself proposed this question; he also found the answer. The

attractive power of a celestial body depends upon its larger or smaller

mass. In our solar system the sun's mass is so much larger than that of

any of the planets, that the balance of attractive power is largely in

his favor; hence the revolving of the planets around him. If the sun

were to disappear suddenly the effect of the attractive influence of the

planets upon one another would be tremendous. There can be no doubt that

they would all begin to revolve around Jupiter, because that planet has

the largest mass. To give some examples in figures,--the sun's mass is

355,499 heavier, while Jupiter's is but 339 times heavier than that of

the earth. It is evident that, the sun's mass being more than a thousand

times larger than Jupiter's, so long as the sun exists the earth will

never revolve around Jupiter.

Yet Jupiter is not without influence upon the earth; and though it is

not able to draw it out of its course round the sun, yet it attracts the

earth to some extent. Observations and computations have shown us, that

the earth's orbit around the sun, owing to the attraction of Jupiter, is

somewhat changed, or, as it is called, "disturbed."

As with Jupiter and the earth, so with all the other planets; their

mutual attraction disturb their orbits round the sun. In reality, every

planet revolves in an orbit which, without this "disturbance," would be

a different one. The computation of these disturbances constitutes a

great difficulty in astronomy, and requires the keenest and most

energetic studies ever made in science.

Perhaps some of our readers may ask here, whether in course of time

these disturbances will become so great as to throw our whole solar

system into confusion? Well, the same question was proposed by a great

mathematician named Laplace, who lived towards the end of the last

century. But he himself answered the question in an immortal work, "The

Mechanics of the Heavens." He furnished the proof, that all disturbances

last but a certain time; and that the solar system is constructed so

that the very attractions by which the disturbances are caused, produce

at the end of certain periods a regulation or rectification; so that in

the end there is always complete order.

After what has been said, it is evident that if one of the planets were

invisible, its presence would still be known to our naturalists, on

account of the disturbances it would cause in the orbits of the other

planets; unless, perhaps, its mass be so insignificant as to render its

power of attraction imperceptible.

And now we may proceed to explain the subject of this chapter.

Up to the year 1846, when Leverrier made his great discovery, it was

believed that Uranus was the most distant planet revolving around the

sun. Uranus itself was discovered by Sir John Herschel in England in the

year 1781. As this planet takes eighty-four years to go round the sun,

its complete revolution had not yet been observed in 1846; in spite of

this, however, the course of Uranus was calculated and known very

precisely, because the attractive force of the sun was known; and all

the disturbances that might influence the planet were taken into

account.

But notwithstanding all nicety of calculations, the real course of

Uranus would not at all agree with the one computed. At that time

already, long before Leverrier's discovery, the idea arose that beyond

Uranus, in a region where the human eye could, in spite of all

telescopes, discover nothing, there must probably exist a planet which

changed the course of Uranus. Bessel, a great astronomer, who

unfortunately for science died too soon, was already on the point of

finding out by computation the unknown disturber. But he died, shortly

before Leverrier's discovery. As early even as 1840, Maedler, in the

city of Dorpat, in Russia, wrote a fine article on this as yet unseen

disturber.

Leverrier, however, began the task and finished it. He computed with an

acuteness that was admired by all men of science. He investigated

whereabout in the heavens that intruder must be situated, so as to be

able to trouble Uranus to such an extent; how fast this disturber itself

must move in its orbit, and how large must be its mass.

We live to see the triumph of Leverrier's being able to discover with

his _mental_ eye, by means of computation only, a planet at a distance

of millions of miles from him.

Therefore let us say: Honor science! Honor the men that cultivate it!

And all honor to the human intellect which sees farther than the human

eye!

PART VI.

METEOROLOGY

CHAPTER I.

SOMETHING ABOUT THE WEATHER.

We presume that in a state of unusual bad weather there are many

persons, who find occasion to reflect on the nature of weather in

general.

A few years ago, we had "green Christmas and white Easter," and spring

was of course far behind when Pentecost arrived. We had still cold and

rainy days, while the nights were frosty; and, if one might judge from

appearances, it seemed that nature had made a mistake, and had not known

of our being then in the month of June, which, with us, is usually a

delightful month.

The sun alone was right. He rose on the 9th of June of that year

precisely at 4 o'clock 30 minutes, as was prescribed to him by the

calendar; and set at 7 o'clock 30 minutes, precisely according to

orders. At that time the sun was hastening towards summer, he lengthened

the days and shortened the nights; but he alone is not capable of

governing the weather, and our friends the astronomers, although they

are able to calculate the sun's course with more precision than the

engineer can the locomotive's, are themselves greatly embarrassed when

asked, "What kind of weather shall we have the day after to-morrow?"

It is unpardonable that some of our almanacs, especially those for the

farmer, contain prophecies about the weather. We cannot be too indignant

against the foolish superstition which this abuse tends to foster. And

what is worse, really shameful, is, that those who print such things do

not believe in them themselves, but consider them a necessity

sanctioned by age and custom, and offer it as such to the credulity of

the public.

The subject of this article on the knowledge of weather, is a science, a

great branch of the natural sciences; but it is a branch just

developing, and therefore has, up to the present time, not yet brought

forth any fruit.

It is very likely that at some future day we shall be able to indicate

in advance the weather of any given place. But for the present this is

impossible; and if from time to time men arise and announce that they

can calculate and determine in advance the state of the weather in any

given place--pretending to consult the planets, etc.--we take it for

granted that they are as unreliable as the weather-prophets of the

almanacs.

We said above that the weather might possibly be determined a few days

ahead; science is at present almost far enough advanced for it. But

there are needed for that purpose grand institutions, which must first

be called into life.

If for the proper observation of the weather, stations were erected

throughout the extent of our country, at a distance of about seventy

miles from each other, and if these stations were connected by a

telegraph-wire, managed by a scientific reliable observer; then we

might, in the middle portion of our country, be able to determine in

advance the state of the weather, though for a short time only.

For the changeableness of the weather depends on the nature and motion

of the air, and on the amount of moisture, and the direction of the

winds. It is mostly occasioned by currents of air which pass over the

earth, producing, wherever they meet, here cold, there heat--here rain,

there hail or snow.

Along a part of the coast of the United States electric telegraphs have

been established. Vessels receive, at a considerable distance, the news

of a storm approaching, together with its velocity and direction. The

electric telegraph being quicker than the wind, the vessels receive the

news in time to take their directions. Before the storm reaches them,

they have been enabled to take precautionary measures for its reception.

This is a great step forward in our new science. But not before the time

when such stations shall be established everywhere throughout the land,

will meteorology manifest its real importance. For it has, like every

other science, firmly established rules, which can easily be calculated

and verified; while, on the other hand, allowances must be made for

changeable conditions which tend to disturb the rules.

We will now endeavor to introduce to our readers these established

rules, and explain the changeable conditions to which we refer.

CHAPTER II.

OF THE WEATHER IN SUMMER AND WINTER.

As we have stated above, there exist fixed rules about the weather;

these rules are simple and easy to compute. But our computations are

often disturbed by a great many circumstances beyond our reach, so much

that we are governed more by exceptions than rules.

These latter are based on the position of our earth with regard to the

sun. They are, therefore, easy to determine, for astronomy is a science

resting on firm pillars; and although nothing in the universe is so far

from us as the stars, yet there is nothing in the world so certain as

our knowledge of the courses of the constellations and their distances.

Many of our readers may be surprised, perhaps, to hear that we know more

accurately the distance from the earth to the sun than the distance from

New York to Cincinnati. Indeed, astronomical knowledge is the most

reliable in the world. No merchant is able to measure a piece of cloth

without being mistaken, to say the least, as much as 1/300 part; while

the uncertainty with respect to distances of bodies in the solar system

amounts to a great deal less than 1/300 part.

Our earth turns on its axis once in every twenty-four hours, and goes

also round the sun once a year. But the earth's axis is inclined towards

the earth's orbit--orbit is the circle which a celestial body describes

in its revolution around another--in such a manner as to cause the

earth, in its orbit round the sun, to be illuminated for six months on

one side, and for six months on the other side of the earth. Hence it

happens, that at the north pole there is continual day during six months

in the year, after which follows uninterrupted winter for the next six

months; in the same way the day on the south pole lasts six months, and

the night following the same length of time. In the middle between both

poles, however, in the regions around the equator, the day has

throughout the year twelve hours; the night, of course, the same; while

in the countries between the equator and the poles, the length of day

and night is, through the whole year, constantly varying.

We, in the United States, inhabit the northern hemisphere; when,

therefore, the time comes that the north pole has day for six months, we

in North America, being situated about half-way between the equator and

north pole, enjoy long days and short nights. The inhabitants of those

countries, however, situated on the southern hemisphere, have at that

time short days and long nights. But when the time comes that there is

six months' night on the north pole and six months' day on the south

pole, then will the inhabitants of the southern hemisphere have long

days, and we long nights.

Intimately connected with the length of day and night are our seasons,

especially summer and winter; for together with the sun's light heat is

also called forth. During our long days, therefore, it is very warm with

us, for the sun's rays heat the soil. During our short days we

experience cold, because the warming light of the sun does not reach our

earth directly. For this reason the northern hemisphere enjoys summer

while the southern has winter; and _vice versa_, when we have

mid-winter, people in the other hemisphere are in the midst of summer.

When we are snowed up at Christmas, and seek joy and elevation by the

cheerful fireside in the brightly-lighted room, we may, perhaps, think

of our friends and relatives who have emigrated to Australia, and the

question may occur to us, how things may be with them this cold

weather, and how they are enjoying the holidays?

Now, would not the uninformed be surprised, if a letter were to arrive

from Australia, written at Christmas, telling how the writer enjoyed

Christmas in his vine-arbor, where he had sought shelter from the

terrible heat of the day, and that he had but late at night gone to his

room, and he could scarcely sleep then on account of the heat, and the

longing for his former home in the United States, where he could always

enjoy cool weather at Christmas.

The uninformed will now learn that Australia lies in the southern

hemisphere, while we are in the northern, and that there they live in

midst of summer, while we are buried in snow. Nor will he now be

surprised when he reads, that it snowed in Australia in the month of

August, and that his friend or relative there reposed by the fireside,

and read the letter from home by the light of the lamp, at the same hour

that we here were taking an afternoon walk in the summer shade.

The heat of summer, however, does not altogether depend upon the length

of the day; nor does the cold of winter upon its shortness; but

principally on this, that during summer-time the sun at noon stands

directly over head; that therefore his vertical rays are enabled to

pierce the soil with intense heat; while in winter-time the sun at noon

stands nearer to the horizon; his rays fall on the earth obliquely,

therefore heating the soil with but feeble power.

We shall presently see that this position of the sun exercises great

influence upon the weather.

CHAPTER III.

THE CURRENTS OF AIR AND THE WEATHER.

In order to fully understand the conditions of the atmosphere, one must

carefully notice the following:

Though the sun produces summer and winter, and although his beams call

forth heat, and the absence of heat causes intense cold on the surface

of the globe, yet the sun alone does not make what we call "Weather."

If the sun's influence alone were prevalent, there would be no change at

all during our seasons; once cold or warm, it would invariably continue

to be so, according to the time of the year. The sun, however, produces

certain movements in the air; currents of air or winds pour from cold

countries into warm ones, and _vice versa_ from warm ones into cold

ones. It is this that makes our sky be cloudy or clear; that produces

rain and sunshine, snow and hail, refreshing coolness in summer and

warmth sometimes in midwinter, as also chilly nights in summer and thaw

in winter. In other words, it is more properly the motion of the air,

the wind, that produces what we call _weather_; that is, that

changeableness from heat to cold, from dryness to moisture, all of which

may be comprised in one name, weather.

But whence does the wind arise? It is caused by the influence of the

sun's heat upon the air.

The whole earth is enveloped with a misty cover called "air." This air

has the peculiar quality of expanding when it becomes heated. If you put

a bladder that is filled with air and tied up, into the pipe of a heated

stove, the air inside will expand so much as to burst the bladder with

a loud report. The warm expanded air is lighter than the cold air, and

always ascends in the atmosphere.

Lofty rooms are therefore difficult to heat because the warm air ascends

towards the ceiling. In every room it is much cooler near the floor than

near the top of the room. This accounts for the singular fact that in

winter our feet, though warmly clad in stockings and shoes or boots,

feel cold more often than our hands, which are entirely uncovered. If

you ascend a ladder in a tolerably cold room, you are surprised at

finding it much warmer above than below in the room. The flies take

advantage of this in autumn, when they are seen to promenade on the

ceiling, because there it is warm as in summer, while near the floor it

is cold; owing to the circumstance that warm air, being lighter than

cold, ascends.

Precisely the same takes place on the earth. In the hot zone near the

equator the sun heats the air continually; hence the air there ascends.

But from both the northern and southern hemispheres, cold air is

constantly pouring towards the equator in order to fill the vacuum thus

produced. This cold air is now heated also and rises, while other cold

air rushes in after. By this continued motion of the air towards the

equator, however, a vacuum is created also at both poles of the earth;

and the heated air of the equator, after having ascended, flows towards

these two vacuums. Thus arise the currents in the air; currents which

continue the whole year, and cause the cold air to move from the poles

to the equator along the surface of the earth; while higher in the

atmosphere the heated air flows from the equator back to the poles.

Therefore the air is said to circulate below from the poles to the

equator, but above to go back from the equator to the poles.

He who is in the habit of noticing phenomena of nature, may often have

observed something of the kind when opening the window of a room filled

with smoke. The smoke escapes above, while below it seems to come back

into the room again.

But this is an illusion which has its origin in the fact, that above the

warm air of the room goes out of the window, and, of course, takes the

smoke with it; below at the window, however, cold air pours in from

without, driving the smoke that is below back into the room. The

attentive observer may also see how the two currents of air above and

below move in contrary directions; while in the middle part they repel

each other, and form a kind of eddy which may be clearly perceived by

the motion of the smoke.

What takes place on our earth is nothing different from this, and we

shall presently see the great influence this has upon our weather.

CHAPTER IV.

THE FIRM RULES OF METEOROLOGY.

The air which is continually rising in the hot zones and circulating

towards the poles and back again to the equator, is the prime source of

the wind. This latter modifies the temperature of the atmosphere; for

the cold air from the poles of the earth, in coming to the equator,

cools the torrid zone; again, the hot air going from there to the poles

heats the colder regions. This accounts for the fact that very often it

is not so cold in cold countries as it really would be, were it not for

this circulation of the air; and that in hot countries we never find the

degree of heat that there would be if the air were continually at rest.

According to what has been said, however, but two different winds would

exist on the earth, and these two moving in fixed directions; one

sweeping over the earth from the poles to the equator, with us called

"North wind," and one from the equator to the icy regions, with us the

"South wind."

But we must add here something which considerably modifies this, viz.,

the revolution of the globe. The earth, it is well known, revolves round

its axis from west to east once in twenty-four hours; the atmosphere

performs this revolution also.

But since that part of the atmosphere nearest to the equator must move

with greater velocity than the part nearer the poles, it may with a

little thinking be easily understood, that the air which goes on the

surface of the earth from the poles to the equator, passes over ground

which moves faster east than the air itself; while, on the contrary,

the air coming from the hot zone starts in an eastern direction with the

velocity it had on the equator; but, as it is moving on, it passes

over that part of the earth which rotates with less velocity.

This gives rise to what are called the _trade-winds_, so very important

to navigation. In our hemisphere the trade-winds come in the lower

strata of the air from the northeast; while in the upper strata they

move towards northeast, they come from the southwest. On the other

hemisphere the trade-winds in the lower strata of the air move in a

northwesterly direction; in the upper they move in a southeasterly

direction.

From this arise our rules respecting the weather.

The idea that many persons have that wind and weather are two things

entirely different, is wrong. Weather is nothing else but a condition of

the atmosphere. A cold winter, cold spring, cold summer, and cold

autumn, do not mean, as some believe, that the earth, or that part of it

on which they live, is colder than usual; for if we dig a hole in the

ground, it will be found that neither cold nor warm weather has any

influence upon the temperature below the surface of the earth. At the

small depth of thirty inches below the surface, no difference can be

found between the heat of the day and the cold of the night. In a well

sixty feet deep no difference is perceivable between the hottest summer

and the coldest winter-day, for below the surface of the earth the

differences of temperature do not exist. What we call Weather is but a

state of the atmosphere, and depends solely upon the wind.

It has been stated already that there are fixed rules of weather, or,

which is the same thing, that there are laws governing the motion of the

winds; but we have added also, that there are a great many causes which

disturb these rules, and therefore make any calculations in advance a

sheer impossibility.

We have seen that these rules are called forth, 1st, by the course of

the sun; 2d, by the circulation of the air from the poles to the equator

and back again; and 3d, by the revolution of the earth, causing the

trade-winds.

All these various items have been calculated correctly; and, owing to

this, we have now a firm basis in meteorology. But in the next article,

we shall see what obstacles are put in the way of this new science by

other things; and the allowances to be made for these disturbances

cannot be easily computed.

CHAPTER V.

AIR AND WATER IN THEIR RELATIONS TO WEATHER.

Let us now examine the causes which disturb the regular currents of air,

and which render the otherwise computable winds incomputable, thus

producing the great irregularities of the weather.

The main cause lies in this, that neither the air nor the earth is

everywhere in the same condition.

Every housewife that but once in her life hung up clothes to dry, knows

full well that air absorbs moisture when passing over, or through, wet

objects. If she wishes to dry her clothes very quickly, she will hang

them up where there is much wind. And she is perfectly right in

maintaining that the wind dries clothes better than the quiet sunshine.

Whence does this come?

From this: dry air, when coming in contact with wet objects, absorbs the

moisture, and by this dries the object somewhat. If there be no wind,

the moistened air will remain around the wet object, and the drying goes

on very slowly. But so soon as a little wind arises, the moist air is

moved away, new dry air constantly takes its place, and coming into

contact with the wet article, effects in a very short time the desired

result.

Hence, it is not heat alone that causes the clothes to dry; for in

winter-time, though it is so cold that the clothes on the line freeze to

stiffness, they dry nevertheless, if it be very windy. It is the wind

which dries them by allowing fresh air to pass through them continually.

For the same reason our housewives open doors and windows after a room

has been scoured, so that by a thorough draft of air, the floor may dry

quickly; a large fire in the stove or fireplace could not effect it so

readily.

From all this we may learn that the air absorbs particles of water. It

will now be evident to every one, why water in a tumbler, standing

uncovered at the open window for a few days, constantly decreases, until

it finally disappears entirely and the tumbler is dry. Where has the

water gone? The air drank it off, little by little, until at last the

tumbler was emptied.

"But," you will exclaim, "what does the air do with all the water it

drinks? The air goes over the whole ocean; over lakes, rivers, brooks,

and springs; over woods and fields, and everywhere it takes in particles

of water. What becomes of them?"

After being absorbed, the particles of water unite and form clouds; then

they fall down in the form of fog, rain, snow, or hail.

Many persons, even highly educated ones, have false ideas about these

phenomena of the atmosphere.

Some think a cloud is a kind of bag that contains the rain which is let

fall by the cloud. This is entirely false. The clouds are nothing but

fogs in the upper regions of the atmosphere; fog itself is nothing but a

cloud immediately over ground.

It is easy to obtain a correct idea of the formation of fog and rain;

one need but observe for one's self.

He who has ever blown upon his hands in winter-time in order to warm

them, will have observed that his hands become moist from his breath. If

a window-pane is breathed upon, it is covered by a thin coat of water.

What is the cause of this? It arises from the fact that the air we

exhale contains water-particles from our blood. We do not see them when

it is warm, because they are airy themselves; everybody knows that they

become visible so soon as the air turns cool; or that they appear like

fog when one is in a cold room in winter; that they form drops when you

breathe upon cold objects; that they freeze and become snow; nay, that

in severe cold weather, after a long walk outdoors, they even cling to

one's moustache like icicles.

This may illustrate, that these particles of water are invisible in the

warm air, but that when the air is colder they appear as fog; when still

colder, as drops of rain; and in very cold weather they turn to snow,

while in severe cold they freeze and form ice.

CHAPTER VI.

FOG, CLOUDS, RAIN, AND SNOW.

The air imbibes particles of water from all parts of the earth; and thus

charged with water it is the same and operates the same as our breath.

So soon as a stratum of air that contains water-particles, meets with a

colder stratum, these airy particles of water immediately flow together

to form fog. But fog, as has been said, is nothing but a cloud. He who

has travelled in mountainous countries, has often noticed this. From the

valley it often appears that the top of a high mountain is wrapped in

clouds; and his curiosity may be excited to ascend the mountain in order

to examine these clouds. But when he arrives there, he sees nothing

whatever either before or behind him but fog, which most assuredly he

has often seen before without so much trouble. The ignorant person who

believes that a cloud is something else than fog, and who fancies that

the clouds which he saw from below have disappeared during his ascent,

leaving but a mist behind, will be no little amazed when he has arrived

at the foot of the mountain again, to see the cloud above as before, and

to perceive that he actually walked among the clouds.

Hence it is understood now, that the particles of water in the air form

fog, or, which is the same, clouds, so soon as they come into a colder

stratum. But the cloud is not rain as yet; the change into rain will

depend upon circumstances that may be easily guessed. If a warmer and

dryer stratum passes over the one containing the newly formed clouds,

then this warmer stratum will absorb the water-particles of the other.

The moist air fares like the wet clothes we spoke of; the warm dry air

absorbs its particles of water. But if a colder stratum of air

approaches the stratum containing clouds, then the water-particles of

the latter are condensed; the cloud becomes small drops of water; these

drops are too heavy to be supported in the air, and they fall down as

_rain_.

During its descent, the drop of rain is steadily increased by the

water-particles of the air through which it passes. Thus it happens,

that rain often arrives at the earth in the form of large drops of

water, while when yet in the air and beginning to fall, it consisted of

tiny drops. It is well known that the rain-drops on the roof are smaller

than those that fall on the street. The difference is so great, that on

the roof of the royal castle in Berlin, Prussia, there falls four and a

half inches less rain during the year than on the square before the

building.

Our readers may now imagine, without difficulty, how in a similar way,

snow is formed. If a stratum of air saturated with moisture meets a very

cold one, the fog begins to freeze, and becomes specks of snow. They,

too, increase while falling, and on arriving upon the earth they are

large flakes.

On the occasion of a lecture about the formation of snow in the

atmosphere, Professor Dove once told an anecdote, which is as

interesting as it is instructive. A musician in St. Petersburg gave a

concert in a large hall, where the fashionable world had assembled in

great numbers. It was an icy cold night, such as is almost unknown with

us; but in the overcrowded hall there was such excessive heat as only

Russians can endure. Soon, however, it became too intense even for them.

The hall was densely crowded; the throng was alarming; several ladies

fainted. An effort was made to open a window, but without success--the

window was frozen fast. A gallant officer devised means; he broke the

window in. And what happened? _It commenced to snow in the concert

room!_ How did this come? The vapor exhaled by the multitude of persons

in the hall had collected above, where the air was hottest. The sudden

entrance of the icy air through the broken window changed the particles

of water into snow. Thus it was this time not heaven, but the upper

space of an unventilated concert-hall, that sent down snow.

In a similar way hail is formed in the atmosphere; this we shall

consider at more length hereafter. At present we must turn our attention

to the influence of these phenomena upon cold and heat; for it is a

known fact, that rain and evaporation are not only engendered by cold

and heat, but, _vice versa_, that rain and evaporation, in their turn,

engender cold and heat in the air.

CHAPTER VII.

HOW HEAT IN THE AIR BECOMES LATENT, AND HOW IT GETS FREE AGAIN.

In the preceding chapter it was shown how warm air produces evaporation,

and how cold air causes rain and snow. In this chapter we desire to

demonstrate how the reverse may take place, viz., the engendering of

cold and heat by evaporation and rain.

Although what we wish to prove in the following is firmly established,

yet it is not easy to make it understood. For this reason many educated

men, who have read much about "free and latent heat," have mistaken

ideas about it.

In order that what we shall explain may be in the reach of every one, we

must again choose our examples from life itself, and request our readers

to come to our aid with their thoughts.

Every one knows how water is boiled. It is placed over the fire, the

heat of which communicates itself to the water and heats it more and

more. Now, where does the heat of the fire go? It is taken up by the

water; thus to speak, the water absorbs the heat. This explains why a

cooking-stove on which a dinner is cooked, does not get near as warm as

it would, if the same quantity of fuel had been used without any cooking

on the stove. For a portion of the heat being absorbed by the meat, it

cannot heat the stove; hence the stove fails to receive the amount of

heat that is used in cooking the meat.

What will be the effect of taking boiling water from the stove and

placing it in the room somewhere? Where will the heat of the water go

then?

We all know that in this case the water cools down by degrees. The water

gives out its heat. Now, it is evident that while on the fire, the water

had absorbed heat; and that it gave out that heat on being put in a

colder place.

But what will become of the water if it is allowed to continue to absorb

heat? What becomes of a pot of water, if, on beginning to boil, it is

not taken off the fire? Does such water continue to absorb heat?

Observation shows that this is not the case. Put a thermometer into

boiling water; it will immediately rise to 212 degrees; let it remain

there ever so long, it will not rise a degree higher. But during that

time there was a brisk fire; it is evident, therefore, that heat was

continually passing into the water. Where, then, is this heat? It has

not remained in the water, or else the thermometer would have continued

to rise. It must be, then, that it has passed away with the burning hot

steam which has been constantly rising and floating about in the room.

Moreover, it is well known that water, when allowed to continue to boil,

decreases in quantity. Our housewives call this "_boiling down_." In

truth, however, the water boils _up_; for, if you notice carefully, a

part of the water, while boiling, is changed into steam, which may be

seen rising from the pot and ascending in the air. The question

naturally arises now, where is the heat that the boiling water has been

continually absorbing? It has not remained in the water, or the

thermometer would have continued to rise. The answer is now evident: the

heat has risen with the steam, and with it floats about in the air; or,

in other words, the heat has been absorbed by the steam; or, which is

the same, the heat has become latent in the steam. Therefore we are

correct in saying, _it takes heat to change water into steam_. We know

now where the heat has gone; it has become latent in the steam.

The next question might be: Can this latent heat become free again?

Certainly it can; and many a good housewife has convinced herself of it

very often, though perhaps she did not philosophize about it. When

touching unawares the spout of the tea-kettle with her hand she felt as

though her hand was wet, and scalded besides. Whence did this come? The

hand was wetted by the steam, which, on coming in contact with the hand,

changed to water again, but in the same moment, also, the steam gave up

its heat to the hand by scalding it. Steam, therefore, when changing

into water, gives its latent heat up again; or, the latent heat becomes

free.

This phenomenon, which may be witnessed in every kitchen, happens in

nature on a larger scale; by what powerful effects it is accompanied, we

propose to show in the next chapter.

CHAPTER VIII.

LATENT HEAT PRODUCES COLD; FREE HEAT, WARMTH.

He who considers how water when heated is transformed into steam, and

how this steam has absorbed the whole portion of heat that was necessary

to form it, will easily understand, that places where vapor is formed

must become cooler. Just as the fire used for cooking purposes cannot

heat the stove, so that portion of the sun's heat which changes the

water on the surface of the earth into vapor, cannot heat the earth.

Hence it follows, that wherever water evaporates, the air _turns cool_,

because the heat, instead of being imparted to the air, is used in

forming vapor; this vapor, then, contains the same portion of heat that

was necessary to form it; or, scientifically speaking, vapor makes heat

latent.

When in summer it is oppressively hot, and a heavy shower comes, it is

often more oppressive during the rain than before; but _after_ the rain

the weather is, as we call it, _cooled off_.

What is the cause of this? After the rain the surface of the earth is

wet, and the moisture begins to evaporate. In other words, the

rain-water changes again into vapor. To do this, heat is necessary, and

is withdrawn from the air and from the surface of the earth; by this

means air and earth become _cool_.

It is very agreeable during the summer-time to have the streets of

cities sprinkled with water, and it is also very healthy, because the

evaporation of the sprinkled water renders heat latent, and thus cools

off the air.

The reverse, however, may also take place. As the housewife's hand is

scalded when the steam changes on her hand into water, that is, as the

steam by turning into water again gives up the heat it possessed, just

so acts nature. When vapor in the air turns into rain, it gives up that

portion of heat which it had held latent, and hence it is, that

_before_ a rain or snow-storm the weather turns warmer.

When in winter it suddenly turns a little warm, that is, when the cold

suddenly diminishes, we know that it is going to snow. The only reason

why it has become warm is this, that in the air above, vapor has changed

into snow, thus giving up its heat, the benefit of which we feel. Thus

in summer-time, when the sun becomes fiercest, people say "The sun draws

water, it will rain." The truth is, that the vapors in the air change

into water, and thus give up their heat; people now think the sun has

become hotter.

Another consequence of this phenomenon is the fact, that in countries

where there is much water, the air in summer is much cooler, because a

great deal of water evaporates there, by which means heat is absorbed or

made latent. In winter the air in such countries is warmer, because much

vapor is changed into water; thus heat becomes free.

It is evident that all this has a great influence upon the weather--an

influence that may be calculated even in advance.

To state an example: The positions of Berlin and London are such, that

the summer-heat and the winter-cold ought to be equal in both places.

But because England is an island in the ocean, that is, surrounded by

large masses of water, the evaporation of water is in London much

greater; hence the summer there is cooler. For the same reason rain and

fog are much more frequent there, and the winter, consequently, is less

severe.

In the course of this work we shall see how similar conditions have very

great influence upon whole countries, and therefore often cause,

contrary to the rule, cold summers and warm winters.

CHAPTER IX.

RULES ABOUT THE WEATHER, AND DISTURBANCES OF THE SAME.

If we cast a glance upon the phenomena of our atmosphere, we find that

they are indeed computable, and that the weather in general may be

foretold, even for large countries, with some degree of certainty. Nay,

there are countries where the weather is not variable at all, but

changes at regular periods and according to fixed rules.

In countries near the equator, where the sun's heat is very strong,

heat, calm, and dryness prevail during the summer-time. This state of

the atmosphere continues uninterruptedly until winter; nor can there be

any frost there in winter, because even then the sun's rays fall with

but little obliquity upon the surface of the earth. But inasmuch as the

sun no longer heats the earth to the same degree, the air ceases to

retain the same amount of heat, and as a great deal of cold air is

constantly passing in from the poles, the vapor spoken of above is, at

that season of the year, changed back into water. Thus, winter there is

merely a long, uninterrupted rainy season.

We see that for the warmer countries the rules of temperature are pretty

constant and sure; there one is not surprised by irregularities of

weather such as occur with us. Summer brings heat, calm, and dryness;

winter, east winds, thunder-storms, and continual rain. The rain once

ceasing, the sun reappears in a few days, and everything begins to bloom

again.

This holds good only for the countries near the equator. The further

you go towards the poles, the more varied become summer and winter, the

length of day and night, heat and cold, and consequently, also, the

condition of the atmosphere and of the weather proper.

A glance upon the map will convince any one, that it is with us that the

weather is most changeable. The reasons for this may now be more closely

examined. Our country lies nearly half way between the pole and the

equator. From our pole we constantly receive a cold wind, the north

wind. And above, in the atmosphere, a warm wind, the south wind, goes

continually from the equator to the pole. Through the rotation of the

earth around its axis from west to east, the north wind becomes an

easterly, that is, a northeast wind; and the south wind in the upper

atmosphere becomes a westerly, or southwest wind. The former, coming

from cold countries, carries no vapor with it; hence, during northeast

wind we have clear sky, or sunshine, but without heat. If this wind

occurs in winter, it brings us dry frost; in daytime the sun shines

splendidly, at night the stars sparkle brilliantly; yet our breath

freezes on our lips. The same wind when prevailing in the first days of

spring, causes us, in spite of the glaring sun, to feel considerably

cold in the shade.

And it is but natural that it should be so.

The wind comes from the north; there ice and snow are just melting, and

the sun's heat being employed for this "melting business," the air

cannot receive much of it.

This kind of weather would be regular with us; but, as we know already,

the heated upper air flows from the equator to the north pole; now we

live in the very region where this upper air, in its descent towards the

poles, at times touches the surface of the earth, thus causing warm

currents of air, which occasionally are followed by cold ones.

Near the equator the cold current of air moves below and the warm one

above; while in our regions, both currents meet near the surface of the

earth, struggle with each other, seek to repel one another, rush and

roll in all directions over the land, and bring us such varieties of

weather as will exasperate all weather prophets, and greatly increase

the difficulty of scientific solutions in meteorology.

In the next chapter we shall endeavor to prove that this state of

affairs, together with the situation of our country, are the main causes

of the changeableness of our weather.

CHAPTER X.

THE CHANGEABLENESS OF THE WEATHER WITH REGARD TO OUR GEOGRAPHICAL

POSITION.

We have endeavored to explain why our weather is so uncertain and

incomputable. As we have seen, it has its origin in this, that in our

regions the warmer equatorial currents of air no longer move _above_ the

colder ones, but that they descend here, and pursue their northern

course alongside and opposing the colder currents. This often gives rise

to a struggle between cold and warm currents. In summer we witness such

combats very frequently. The sky is at first bright; the sun sends down

his most powerful rays; in the shade we are refreshed by a strong

draught, which keeps the sky clear, and free from clouds. Suddenly there

comes a calm. Even in the shade the heat now becomes intolerable. The

trees stand immovable; no leaflet stirs. The complete calm becomes

unendurable, and causes anxiety. "Always a calm before a storm," say the

people, and hasten to seek shelter in their houses--and well! for it is

not long before a counter wind commences to blow. The weathercock turns

round, the dust in the streets is whirled up in eddies, and here and

there rises in clouds to the house-tops. Suddenly clouds are seen to

form themselves; the trees shake their crowns; the leaves rustle, and

before one is aware of it, we have storm, thunder, and violent rain,

which cool off the earth.

Whence came this weather; more especially, whence came the calm

preceding it, and the whirlwind following?

There were two opposite currents of air, which for a time avoided each

other, but at length met over our heads. Each current at first pressed

on the other with equal force, so that they mutually were brought to a

stand-still; this we called a _calm_. But such an equilibrium does not

last long, for one current must in the end overcome the other; they

whirl through one another, raise the dust in high columns, seize the

trees and give them a thorough shaking. The cold current changes the

vapor of the warm current into clouds, then into rain. The pouring down

rain immediately sets free the heat. At this stage electrical phenomena

are witnessed, such as lightnings, claps of thunder, and concussions of

the air. And this continues until one current of air has carried the

victory over the other; not till then does the weather become quiet

again.

Besides these opposing currents of air, which come from the north and

south, there are other causes disturbing our weather, viz., the

geographical position of our country in regard to the east and west.

A glance on the map reminds us that our continent borders, on the east

and west, on that immense waste of water, the ocean. We know now that

the air above the water is always saturated with vapors, while the air

over the land is comparatively dry. And moist air contains heat, dry air

does not; both, however, are continually tending towards equilibrium and

wish to exchange temperatures from each other. As our dry air is

surrounded on both sides by moist air, it is evident that we must more

or less partake of both heat and cold; but it moreover accounts for the

happy circumstance that we have much rain; hence our soil is well

watered, and this is a blessing to any country.

CHAPTER XI.

ABOUT THE DIFFICULTY AND POSSIBILITY OF DETERMINING THE WEATHER.

Having now explained the rules referring to the conditions of our

weather, and proved that owing to the geographical position of our

country, to determine the weather in advance, is difficult, we wish to

examine this difficulty a little more closely in pointing out the wrong

direction which has hitherto been pursued in the science of meteorology.

The main difficulty in predicting the weather for any given place

consists in this, that a change in the atmosphere need not originate in

the place where it occurs. Thus, to-morrow's weather in New York is not

a consequence of the condition of the air as it exists there to-day; for

the air is continually moving, and, owing to many disturbances, is

carried over city and country. We have no sure means of ascertaining

whence the wind will come to us to-morrow. All we know is, that from all

sides currents of air are moving simultaneously; from the north pole a

cold current, from the equator a warm one, from the ocean one saturated

with moisture. All these winds are in continual commotion, and have the

characteristics of the neighborhood from which they come. If from the

state of the weather in New York to-day it were desired to predict the

weather there for to morrow, one ought to be able to overlook a space of

about a thousand miles around; in other words, it must first be

ascertained what is the state of the atmosphere within about a thousand

miles of the city. Besides, there should be known the direction of all

the winds within this wide space, and their speed, and whether they

contain much moisture or little. Not without this information could a

calculation be made about the velocity with which a change of the

weather would take place in New York; what results the meeting of two or

more currents of air might call forth; and what kind of weather this

might produce there.

Weather, therefore, for the present state of meteorology, is but a

subject of investigation into the existing condition of existing

phenomena, and not a subject of prediction of coming phenomena. It is

true, there are general rules by which a proximate success in predicting

may be obtained. If winter begins mild, or, better, if southwest winds

and rain prevail till the middle of January, it is very likely that this

will be counterbalanced by a northeast wind in the latter part of the

winter. The saying, therefore, is correct, "green Christmas and white

Easter;" but this rule is by no means infallible, the counteraction may

be accelerated by violent storms, or greatly retarded by mild currents

of air.

Not before the time that meteorological stations are established

throughout the land, and connected by electric telegraphs--a project

which to us may seem immense, but to our children will appear very

simple and natural--not before that time will a city like New York, for

example, receive timely information about the conditions of the currents

of air at all the stations. At each of these places the force of the

current, its warmth, moisture, and weight will be accurately ascertained

by instruments. Then, and then only, we may calculate what currents will

meet and where, and what effects the meeting will have. If this be done

on Saturday, the Sunday papers will be enabled to state precisely

whether the church-goers must provide themselves with umbrellas or

parasols.

But not for Sunday alone will this be of importance. It will be long

after their establishment, that such weather-stations, connected by

telegraphs, will prove their real efficiency and blessing; and our

descendants, perhaps, will wonder how we could live without an

institution, which to them will appear as simple and natural as do to us

gaslights and railroads, which by our forefathers would have been

rejected as idle dreams or works of witchcraft.

CHAPTER XII.

THE FALSE WEATHER-PROPHETS.

We wish to speak here a few words about the false methods, that have

hitherto been applied to the investigation and foretelling of the

weather.

The weather prophecies of the almanac are a disgrace to our advanced

age. Those who still print them deserve that their productions should

nowhere find sale. We are not of those who expect everything of the

magistrates and their orders; but an example should be set to prevent

the publishers from dishing up to the people such absurdities.

Some of these wily prophets pretend to read their predictions in the

course of the planets. For this purpose, they have divided the planets

into two classes, according to their positions in regard to the earth

and sun: 1st, those that produce cold, and 2d, those that produce heat.

By this means they pretend to prophesy how many degrees of heat or cold

there will be every day at sunrise or sunset.

When critically analyzed, these prophecies prove to be theoretically and

practically nothing but charlatanry.

It is beyond all doubt that the position of the planets is, to state an

example, for Boston the same as for the city of Washington; if there are

any heat or cold-producing planets, they would have the same effect at

Boston that they would at Washington. But this is not the case. Boston

has often cold weather when in Washington it is very warm, and _vice

versa_. Besides such a heating or cooling influence of planets would be

perceivable on every spot of the earth alike which again is not

warranted by facts. On the contrary it often happens that when cold

winds are passing over one part of the country, warm winds are passing

over another. It is almost certain that cold winters in Europe always

accompany warm winters in America; and again, that cold winters in

America usually accompany warm ones in Europe. On a closer examination

of the facts in the case, we must conclude that, on the whole,

weather-prophets take things very easy. Noting the mean heat of each

day, and trusting to their good luck, they prophesy one or two degrees

above or below. Now, there is no great risk in doing this, and as a

matter of course such prophecies are realized one out of two. But at

times, almanacs announce an extraordinary increase of cold or heat for a

given day, although the situation of the planets does not change

suddenly in one day. Then, their predictions very seldom prove to be

correct.

In such cases the almanac-makers know how to manage affairs. The country

being very large, they send for information to those places where

observations on the weather are made. It is almost certain that

somewhere in the land their prophesy has come true. Very likely the cold

may have increased extraordinarily in the course of a day at New York,

Boston, Chicago, Cincinnati, or St. Louis, etc., afterwards the

weather-prophets compare their predictions with the results of

observation in the various cities, and publish whatever of them are

found to have been true.

CHAPTER XIII.

HAS THE MOON INFLUENCE UPON THE WEATHER?

The idea that the moon exercises an influence upon the state of the

weather is very general, not only with the people, but also among the

better educated. What induces them to entertain it, is not real

observation of nature, but a belief which is not without a semblance of

truth. If, they say, the moon has enough influence upon our waters to

produce tides, it must exercise a still greater influence upon the sea

of air surrounding us, and hence it must be of the greatest importance

to our weather.

This is, however, an illusion. A long time ago it was proved by Laplace,

that tides are caused by the great weight of a liquid. If the ocean were

filled with mercury instead of water, the tides would reach a formidable

height. Tides, then, do exist in the atmosphere, but in comparison much

less than in the water, because the air is so much lighter. It happens

that we do not live on the surface of the atmosphere, but in the lowest

strata of this airy sea; and in these strata, where the weather

manifests itself, the effect of the tides in the upper air is so

insignificant, that nothing of it has yet been discovered in spite of

most diligent barometer observations.

Learned men have had such a respect for this popular belief, that

thorough observations and investigations have been made in order to

settle the question.

Those investigations were of three kinds:

1st. What influence with regard to heat and cold has the nearness or

remoteness of the moon upon our weather? 2d. What influence has the

same upon rain or dryness in the atmosphere? 3d. Has the change of the

moon any bearing upon the variability of our weather?

For the reply to these questions, some naturalists have made use of the

minutest observations for a period of nearly forty years; during which

time the temperature, pressure, and moisture of the air have been

measured daily.

These observations have been scrupulously examined; the conclusion

arrived at is, that the moon is not quite without influence upon the

state of our atmosphere; but this influence is so very small, that it is

not brought to bear at all on meteorology.

When the moon is nearest to the earth, it is certainly a little colder

than when she is farther off; but the decrease of heat amounts in the

average scarcely to one-fifth of a degree, and this is a quantity

entirely imperceptible in our weather. As to rain, it is a little less

frequent in the time of the moon's greatest distance from the earth; but

this difference, too, is imperceptibly small. In one thousand

rain-storms there are four hundred and eighty-eight during the moon's

greatest distance, five hundred and twelve during her nearest. As to the

pressure of the air, it is during the moon's greater distance somewhat

greater than when she is nearer, but this difference is still less than

the preceding ones, so much so that a common barometer does not even

indicate it.

The most thorough investigations have been made about the influence of

the waxing and waning moon upon the weather, because it was on this

subject that the greatest illusion prevailed. The result here is

likewise, that scarcely any difference exists, and that it is a mere

superstition for people to maintain, that when the moon changes, the

weather changes also. The change in the moon, moreover, does not take

place all of a sudden, but with great regularity from day to day, from

minute to minute; while the weather, especially with us, changes often

very abruptly.

It is therefore certain, that in meteorology one has only to observe the

earth and her position with regard to the sun, together with the

currents of air and the position of land and water. Other phenomena of

the atmosphere may be entirely omitted.

PART VII.

OUR ARTICLES OF FOOD.

CHAPTER I.

THE RAPID RENEWAL OF THE BLOOD IS AN ADVANTAGE.

Our articles of food are also called _articles of life_, and very

properly so; for that which lives in us is, indeed, nothing but food

transformed into ourselves.

According to this, it is very easy to determine what a man must eat in

order to live; what kind of food can best maintain his health; what

constantly renews his working-power; what compensates for the loss he

experiences by emission of breath, perspiration, and excretions.

This easy task many have proposed to themselves. They believe they have

solved the problem, if they can but prove that all parts of the human

body are fed by the blood; and, the constituents of the blood being well

known, they believe they have done enough, if they designate that food

as the most proper for man which contains the constituent parts of the

blood, or which, by digestion, may be changed into blood.

As a general thing this is true; yet it is not sufficient to give the

necessary information about the principal articles of our food.

The poor Irishman, who lives almost exclusively on potatoes, has as much

blood in his body as the Englishman, whose workmen threaten him with a

strike, if they do not earn enough to have a piece of meat and a good

glass of beer for breakfast. The Irishman's blood contains quite the

same elements that the Englishman's does, and yet their food is very

different; and the Irishman is as justly called "poor," as the

Englishman is said to be "well fed."

It is evident that the blood alone does not account for this, nor can it

do so. There must be other additional items; and these we shall try to

learn before we speak of the different articles of food and their worth.

The first principle which we must set up before all others, runs thus:

Nutrition does not depend on the blood, but rather on its quick renewal.

The blood resembles the capital which a man possesses. No one can live

on his capital without consuming it; he must live on the interest of the

capital; he must live by constantly turning the capital over. And so

must it be with the blood. The comparison seems so perfect, that we can

illustrate our idea best by an example.

Imagine two merchants, each of whom has but a hundred dollars. Both

merchants are therefore equally rich in capital. But there is the

following difference between them: the one goes to the country twice a

week and buys cattle and brings it to market, where he sells it again.

By doing this he realizes every time five dollars on his capital. The

other establishes a notion-store, buys himself a hundred dollars' worth

of goods, which he sells in a month, and thereby gains twenty-five

dollars. Now, which of these two fares the better? The notion-dealer,

who with his hundred dollars has earned twenty-five dollars, or the

cattle-dealer, who gained but five? Most assuredly the cattle-dealer.

For while the other has twenty-five dollars to live on, the

cattle-dealer has eight times five, or forty dollars. Whence does this

come? In a month the notion-dealer turns over his capital but once,

while the cattle-dealer turns his eight times.

The same holds good with the Irishman and the Englishman. Both have the

same quantity of blood; it is their capital, and the same for both. But

the renewal is not the same. The Englishman works vigorously and eats

vigorously. When he works, he spends his capital, his blood; by every

blow of the hammer particles of his body are wasted; the activity of his

body is great and his appetite is great. He invests his capital again

and again in rapid succession, and he takes it in just as rapidly and

fares well with it. The poor, unhappy Irishman, however, spends his

blood but very slowly; he does not work; he eats potatoes, which, taken

alone, are bad food; thus, he invests his capital very slowly and takes

it in again very slowly; and though the capital is in both cases the

same, its slow renewal is the cause of the Irishman's being miserable,

dull, and lazy, while the Englishman is sound in body and soul.

Therefore the blood alone is not all, but its rapid consumption and

renewal is the most important object.