COLUMBUS, COPERNICUS, GALILEO AND OTHERS
Long before the Christian era the Chinese used pivoted magnetic needles
to indicate absolute direction to them; but that they possessed or
had invented the mariner's compass, there is considerable doubt. The
history of the invention of the mariner's compass has not yet been
written. It is not known when, or where, or by whom it was invented.
It is well-known, however, that the mariner's compass was in use in
the Mediterranean Sea in the early part of the fifteenth century A. D.
Guided by it, the navigators of that day pushed far out from land.
The first great navigational feat that followed the invention of the
compass was that performed by the Portuguese, Bartholomew Dias, who
conceived the idea of reaching India by going around Africa, and
sailed down the west coast of Africa as far as its southern end,
later called the Cape of Good Hope. It was a tremendous undertaking,
and it had tremendous results; for it demonstrated the possibilities
of great ocean voyages, proved that the road to India was very long,
and led to the expedition of Columbus, six years later. It was also a
great invention, both in brilliancy of conception and excellence of
execution, although Dias did not reach India.
The second great navigational feat was performed by Christopher
Columbus in 1492. Before that time it was conceded by most men of
learning and reflection that the earth was spherical; and it was
realized that, if it was spherical, it might be possible by sailing to
the westward to reach India, the goal of all commercial expeditions in
that day. Columbus is not to be credited with the first conception of
that possibility.
[Illustration: Portuguese Voyages and Possessions]
But that conception rested undeveloped in the minds of only a few men.
Had it not been for Columbus, or some man like him, it would have
remained undeveloped and borne no fruit. The Savior in his parable
tells us of the sower who went forth to sow, and tells us also that
most of the grain fell on stony ground. So it is with most of the
opportunities that are offered to us every day; and so it is even
with most of the visions that are placed before our minds. But the
Savior tells us also of other grains that fell on good ground and bore
abundant fruit. Such are the conceptions that the great inventors have
embodied; such was the conception that fell on the good ground of the
mind of Christopher Columbus.
The conception that came to him was not of the possibility that someone
could sail west and eventually reach India, but of preparing a suitable
expedition himself and actually sailing west and reaching India. The
conception must have been wonderfully powerful and clear, for it
dominated all his life thereafter. But he could not make others see
the vision that he saw. For many years he went from place to place,
trying to get the means wherewith to prepare his expedition. He made
only a few converts, but he did make a few. Some of these exerted their
influence on Queen Isabella of Spain. She, together with her husband
Ferdinand, then supplied the money and other necessaries for the
expedition.
The invention of the gun was followed by the invention of printing in
1434, and this by the discovery of America in 1492. These three epochal
occurrences started the new civilization with a tremendous impetus.
This impetus was immediately reinforced by the voyage of the Portuguese
Admiral, Vasco da Gama, around the Cape of Good Hope to India in
1497-1498, and the circumnavigation of the globe by Ferdinand Magellan
in 1519-1522.
The immediate practical influence of da Gama's feat was almost to kill
the commerce of the cities of Italy and Alexandria with India by way
of the Red Sea and the Indian Ocean, and to transfer the center of
the sea-commerce of the world to the west coast of Europe, especially
Portugal. Near the west coast it has rested ever since; though but
little of it stayed long with Portugal.
While Magellan's voyage was not quite so important as the discovery of
America, it was not immeasurably less so; for it set at rest forever
the most important question in geography,--was the earth round or
not? The voyage of Columbus had not answered it, because he returned
by the same route as that by which he went. But Magellan started in
a southwesterly course, and one of his ships again reached home,
coming from the east. The Victoria had circumnavigated the globe! Only
eighteen men and one ship returned. The other ships and the other men
had perished. Magellan himself had been buried in the Philippines.
The news of Magellan's great exploit and the stories that came to
Europe of the riches beyond the sea, resulted soon in an idea coming
to the mind of Hernando Cortez, the development of that idea into a
concrete plan, and the making of a complete invention. This was a
plan by which he should head an expedition to a certain part of the
New World, and "convert" the heathen dwelling there; doing whatever
killing and impoverishing and general maltreatment might be found to
be convenient or desirable. The invention worked perfectly; some
half-savage Indians of what we now call Mexico were "converted," many
were killed, and untold treasure was forcibly obtained.
The success of this invention was so great that Francisco Pizarro was
inspired to copy it, and to try it on some Indians in a country that
now we call Peru. Whether Pizarro improved on Cortez's scheme, or
whether the conditions of success were better need not concern us now:
the main fact seems to be that Pizarro was able to convert and kill and
impoverish and generally ruin more effectively than Cortez.
Following Cortez and Pizarro, many expeditions sailed from Spain to
the West Indies, Central America and South America, and carried out
similar programs. The two principal results were that those parts
of the world were soon dominated by Spain, and that the people of
Spain received large amounts of gold and treasure. The main result to
them was that they succumbed under the enervating influence of the
artificial prosperity produced, and rapidly deteriorated. By the end of
the hundred years' period after Columbus discovered America, Spain was
clearly following the downward path, and at high speed.
One of the early results of the invention of printing was an increased
ability of people separated by considerable distances to interchange
their views; and a still greater though allied result was an increased
ability of men of thought and courage to impress their thoughts upon
great numbers of people. At the time when printing was invented, the
Church of Rome had ceased to dominate European nations as wholly as it
had done before; but it exercised a vast power in each country. This
was because of its prestige, its hold on the clergy and the Church
property, and its authority in many questions connected with marriage,
wills, appointments, etc. This was resented, but impotently, by the
various sovereigns.
It was realized also (and it came to be realized with increasing
clearness toward the end of the fifteenth century) that there were many
grave evils and scandals in the Church, even in the highest quarters.
The printing-press lent itself admirably to the dissemination of views
on this matter: so that there gradually grew up a strong and widespread
feeling of discontent. But despite considerable friction as to the
limits of their respective functions, the Church and the State were so
intimately allied in every country, and each realized so clearly its
dependence on the other, that no movement of any magnitude against even
the acknowledged evils had been able to gain ground. No man appeared
who was able to conceive and execute a plan that could successfully
effect reform.
But such a man appeared in the year 1517, whose name was Martin
Luther. He was a poor monk; but a knowledge of virtually all there
was to know lived in his mind, coupled with imagination to conceive,
constructiveness to plan, and courage to perform. In that fateful year,
1517, the Pope sent agents through the world to sell "indulgences,"
which remitted certain temporal punishments for sin, in return for
gifts of money. The agent who was commissioned for Germany carried out
his work with so little tact and moderation, that he made the granting
of indulgences seem even a more scandalous procedure than it really
was. Luther had been preaching the doctrine of a simple following of
the teachings of the Savior, and deprecating a too close adherence to
mere forms and ritual. He now seems to have conceived a clean-cut plan
of effective action; for on the evening before the indulgences were to
be offered on All Saints Day, in the Church of Wittemberg, Luther nails
on the door his celebrated ninety-five theses against the sale. The
printing-press reproduced copies of these in great numbers throughout
Germany. A definite sentiment antagonistic to the indulgences developed
rapidly, and a general movement toward the reform of the abuses in the
Church took shape. Luther was threatened with excommunication by the
Pope in 1520, but he burned a copy of the "papal bull" in a public
place on December 10 of that year.
The emperor of Germany convened a meeting of the Diet at Worms in 1521,
at which he exerted all his powers to make Luther retract: but in vain.
So great a following did Luther now have that, though the emperor put
him under ban, and all persons were forbidden to feed or give him
shelter, he was cared for secretly by men in high position, until he
voluntarily came out of hiding, and appeared in Wittemberg. The emperor
called a meeting of the Diet at Spires in 1526, and another meeting
in 1529. Both meetings had for their object the suppression of the
movement begun by Luther. It was against a decree made by the second
Diet that certain high officials and others made the famous protest,
that caused the name to be affixed to them of Protestants. This name
has been perpetuated to this day.
As is well known, the movement resulted, after nearly a hundred years
of disturbed conditions, in a series of wars, called "The Thirty Years'
War" that began in 1618, and ended with the Peace of Westphalia in
1648. This Peace marked the end of the Reformation period, and resulted
in establishing Protestantism in North Germany, Denmark, Norway,
Sweden, England and Scotland.
The influence of Luther's conception with its subsequent development
was thus definite, widespread and profound, even if regarded from a
merely religious point of view: but the influence it had on religion
was only a part of its total influence. In words, the protest was
against certain abuses in the Roman Church; but in fact it was against
a domination exercised over the minds and souls of men. Luther's
influence was in reforming not only the Roman Catholic Church and the
practice of the Christian religion throughout Europe, but also the
conditions under which men were allowed to use their minds.
While the inventions in mechanism, religion, etc., which we have just
noted were going on during the fifteenth and sixteenth centuries,
others were going on in the realm of science. The movement was begun
about 1507 by a young man named Nicolas Copernicus, who was executing
the dissimilar functions of canon, physician and mathematician in
the little town of Frauenberg in Poland. Copernicus at this time
was thirty-four years old, but he had even then devoted the major
activities of his mind to astronomy for several years. Naturally,
his efforts had been devoted to mastering whatever of the science
then existed. The efforts of most people in dealing with any subject
end when they have gone thus far--and very few go even thus far. But
Copernicus noted that, while the Ptolemaic System (suggested, though
probably not invented by the Egyptian king) was the one generally
accepted, it did not account for many of the phenomena observed; that
none of the other systems that had been suggested afterward explained
matters more satisfactorily, and that no one of the systems was in
harmony with any other.
Thereupon this daring young man conceives the idea of inventing a
system of astronomy himself, in which all the movements of the heavenly
bodies should be shown to be in accordance with a simple and harmonious
law. Seizing on this idea, he proceeds at once to develop it; and he
works on it until death takes him from his labors in 1543 at the age of
seventy.
The whole civilized world had virtually accepted the Ptolemaic
Theory,--at least, the part of it which assumed that the earth was the
center of the universe, the sun and stars and planets revolving around
it. Copernicus invented the theory that the sun was the center, that
the earth and the other planets revolved around it, and that the earth
revolved on its own axis once in twenty-four hours. So great was the
insistence of the religious bodies in adhering to the Ptolemaic Theory,
so set were the minds of all men of high position on it, that though
Copernicus wrote a book expounding his own theory, he did not think it
wise to publish it. He seems to have completed the book in about 1530.
He did not publish it till 1543. Just before its printing was finished,
Copernicus was taken ill. The first volume was held before him. He
touched it and seemed to realize dimly what it was. Then he relapsed
into torpor almost immediately, and soon died.
It is interesting to note that Copernicus was not the first to conceive
the idea that the earth turns on its own axis, or that the earth
revolves around the sun, any more than Bell was the first to conceive
the idea that speech could be transmitted by a suitable arrangement of
magnet, diaphragm and electric circuit. But Copernicus was the first to
invent a system of astronomy that was like a machine. It was a usable
thing. It could be made to explain astronomical phenomena and predict
astronomical events correctly.
It may be well to remind ourselves again that no application for patent
will be granted by our Patent Office unless the invention is described
and illustrated so clearly and correctly that "a person skilled in
the art can make and use it;" and to realize that this admirable
phraseology may be utilized to distinguish any other novel endeavor of
man entitled to be called an invention from any other not so entitled;
for no system, no theory, no religion, no scheme of government,
regardless of how attractive it may be, is entitled to be called an
invention, unless, like the Copernican System, "a person skilled in the
art can make and use it."
Shortly after Copernicus, came Johann Kepler, who was born in
Württemburg in 1571, and died in 1630. He had been a pupil of Tycho
Brahe, who did not succeed in making any great invention or discovery,
but who did collect a great amount of data. Utilizing these, Kepler
devoted many years to the study of Copernicus, and tried to invent a
system which would explain some facts of astronomy that the system
of Copernicus did not explain, notably the non-uniform speed of the
planets. The main result of his labors was the famous Kepler's Laws,
which were
"1. The orbits of the planets are ellipses having the sun at
one focus.
"2. The area swept over per hour by the radius joining sun and
planet is the same in all parts of the planet's orbit.
"3. The squares of the periodic times of the planets are
proportional to the cubes of their mean distances from the
sun."
These three discoveries, enunciated in three interdependent, concrete
laws, constituted an invention which, while it was merely an
improvement on Copernicus's, was so great an improvement as almost
to make the difference between impracticability and practicability.
Without this improvement, astronomy would not be what it is, navigation
would not be what it is, the regulation of time throughout the world
would not be what it is, and the present highly intricate but smoothly
running machine of civilization could not exist at all, except in a
vastly inferior form. The machine of civilization is dependent for its
successful operation on the good quality and correct design of every
other part. So is every other machine; for instance, a steam-engine.
The Copernican System was not recognized for more than a century.
It was, in fact, definitely rejected, and people were subjected to
punishment and even torture for declaring their belief in it.
One of the amazing facts surrounding Copernicus's invention was that
he carried on his observations with exceedingly crude appliances. _The
telescope had not yet been invented._
Who invented the telescope is not definitely known; but it is probable
that both the telescope and the microscope (compound microscope)
were invented by Jansen, a humble spectacle-maker in Holland. Both
inventions were made about the year 1590, and were of the highest order
of merit from the three main points of view,--originality, completeness
and usefulness. Few inventions more perfectly possessing the attributes
of a great invention can be specified. The originality of the
conception of each seems unquestionable; the beautiful completeness of
the embodied form of each was such that only improvements in detail
were needed afterward; and, as to their usefulness, can we even imagine
modern civilization without them both?
The interesting fact may now be called to mind that, although many men
who lived in Jansen's time were loaded with honors and fame and wealth
and glory, the inventor of the telescope and the microscope received
no reward of any kind that we know of; and his fame has come to us so
imperfectly that we are not even sure that Jansen was his name.
The man usually credited with the invention of the telescope is
Galileo, though Galileo himself never pretended that he invented it,
and though historical statements are clear that he heard that such
an instrument had been invented, and then designed and constructed
one himself in a day. It would be interesting to know just how much
information Galileo received. It seems that his information was very
vague. If so, a considerable amount of inventiveness may have been
required, besides a high order of constructiveness. But the mere fact
that Galileo knew that such an instrument had been invented caused his
mental processes to start from an image put into his mind by an outside
agency and not from his own imagination. Galileo's work did not begin
with conception, and therefore it was not an invention.
Galileo was one of the foremost and most ardent supporters of the
Copernican Theory; and it was on his skilful and industrious use of
the telescope in making observations confirming the theory that his
fame mainly rests. As late as 1632, nearly a century after Copernicus's
doctrine had become known, Galileo was compelled by threat of torture
to recant, and was condemned to imprisonment for life.
The influence of inventions on history has been greater and more
beneficial than that of any other single endeavor of man. Yet most
inventions have been resisted. _The invention of Copernicus was
resisted for more than a century by the organization commanding the
greatest talent and character and learning that the world contained._
The extraordinary access of mental energy in Europe about the beginning
of the seventeenth century is illustrated by another invention
virtually contemporaneous with those of Copernicus and Jansen, and also
in the line of mathematical research. This was the invention by Baron
John Napier of logarithms.
It was a curious invention--an invention the like of which one cannot
easily specify; for the thing invented was not a material mechanism,
or a theory, or anything exactly like anything else. It is difficult
to classify a logarithm except as a logarithm:--yet Napier did
create something; he did make something exist that had not existed
before; he did conceive an idea and embody that idea in a concrete
machine. That machine, in the hands of a man who understood it, could
supply extraordinary assistance in making mathematical calculations,
especially calculations involving many operations and many figures, as
in astronomy. It has been in continual use since Napier invented it,
and is used still. In order to indicate the simplicity and the value
of Napier's invention, it may assist those who have forgotten what
a logarithm is, or who have been so fortunate as never to have been
compelled to study about them, to state that logarithms are numbers so
adapted to numbers to be multiplied, divided, or raised to any power,
that one simply adds their logarithm, subtracts one logarithm from the
other or multiplies or divides a logarithm by the number representing
the power, and then notes in a table the number resulting, instead of
going through the long process of multiplying, dividing, squaring,
etc. Of course, in the case of small numbers, the use of logarithms
is not only unnecessary but undesirable; but in the case of the long
numbers used in astronomy, and even in navigation, logarithms are
inexpressibly helpful and time-saving. The mental feat of Napier
consisted in conceiving the idea of accomplishing what he subsequently
did accomplish, and then constructing and producing the "logarithmic
tables" that made it possible.
Another indication of the new intellectual movement in Europe was the
experiments, deductions and inventions of William Gilbert, an English
physician, who lived from 1540 till 1603. According to the use of
the word invention followed in this book, only two actual inventions
can be credited to Gilbert, that of the electroscope and that of
magnetization. Gilbert's work was valuable in the highest degree, more
valuable than that of most inventors; and yet it was more inductive
and deductive than inventional. It is not the purpose of this book to
suggest that invention has been the only kind of work that men have
done which has had an influence on history; and the work of Gilbert
gives the author an opportunity to emphasize the value of certain
work which is not inventional. At the same time, the author cannot
resist the temptation of pointing out that Gilbert's work was original
and constructive, that it hovered around the borders of invention,
and that it did more to assist the inventors of the electric and
electro-magnetic appliances that were soon to follow, than the work of
almost any other one man.
The full influence of Gilbert's work was not apparent for many years;
not, in fact, until the discoveries and inventions of Volta, Galvani
and Faraday showed the possibilities of utilizing electricity for
practical purposes. Then the facts which Gilbert had established, and
the discoveries built upon them afterward, were the basis of much of
the work of those great men, and of the vast science of electrical
engineering that resulted.
The inventions made before the opening of the seventeenth century A.
D., wonderful as they were, were quite widely separated in time, and
seem to have been wholly the outcome of individual genius, and not the
result or the indication of any widespread intellectual movement. But
soon after it opened, the influence of printing in spreading knowledge
became increasingly felt, and inventions began to succeed each other
with rapidity, and to appear in places far apart.
In the beginning of the seventeenth century, certain writings appeared
in England that took great hold on the minds of thinking men, not only
in England, but throughout Europe. The name of the author was Francis
Bacon.
It would not be within the scope of this book even to attempt to
analyze the philosophy of Bacon, to differentiate between it and
the philosophy of Aristotle or any other of the great thinkers of
the world, or to try to trace directly the influence of Bacon's
philosophy on his own time and on future times. It is obvious,
however, that Bacon invented a system of inductive reasoning that
assisted enormously to give precision to the thoughts of men in his
own day, by convincing them of the necessity of first ascertaining
exact facts, and then inferring correct conclusions from those facts.
This seems to us an easy thing to do, looking at the matter in the
light of our civilization. But it was not easy, though Bacon's high
position gave him a prestige exceptional for a philosopher to possess;
and this smoothed his way considerably. Men had not yet learned to
think exactly. The efforts of even the great minds were of a groping
character; and fanciful pictures made by the imagination seem to
have intertwined themselves with facts, in such a way that correct
inferences (except in mathematical operations) were hardly to be
expected. Bacon insisted that every start on an intellectual expedition
should be made from absolutely indisputable facts.
The first effect of such teaching was to make men seek for facts. Not
long afterward, we find that many men were making it the main business
of their lives to seek for facts from Nature herself. This does not
mean that men had not sought for facts before from Nature, or that
Bacon alone is to be credited with the wonderful increase in the work
of research and investigation that soon began.
Bacon's principal book was published in 1620, and called the "Novum
Organum," or "the new instrument." It was obviously an invention, for
it was a definite creation of a wholly new thing, that originated in
a definite conception, and was developed into a concrete instrument.
That Bacon so regarded it is evident from the title that he gave it.
Furthermore, he described it as "the science of a better and more
perfect use of reason in the investigation of things and of the true
aids of the understanding." Bacon was a patient of Dr. Harvey, who
discovered the circulation of the blood; and it would be strange indeed
if Bacon's philosophy did not give to Harvey a great deal of guidance
and suggestion that furthered his experiments.
William Harvey discovered the fact that the blood circulates in the
bodies of living animals. This declaration stated by itself would
convey to the minds of some the idea that Harvey discovered it,
somewhat as a boy might discover a penny lying on the ground. The first
definition of the word discover in the _Standard Dictionary_ is "to
get first sight or knowledge of"; so that the mere announcement that
an investigator has "discovered" something gives to many people an
incorrect idea of his achievement. Harvey discovered the fact of the
circulation of the blood after years of experimentation and research on
living animals, and by work of a most laborious kind. His conclusions
were not accepted by many for a very considerable period; but he was
fortunate, like Bacon, in holding a position of such influence and
prestige, that he escaped most of the violent opposition that inventors
usually meet.
Harvey's discovery did not of itself constitute an invention; but the
embodiment of that discovery in a concrete theory, so explained "that
persons skilled in the art could make and use it," did constitute
an invention of the most definite kind. The whole influence of that
invention on history, only a highly equipped physician could describe;
but, nevertheless, one may feel amply justified in stating that its
influence on the science and practice of surgery and medicine, and on
the resulting health of all the civilized nations of the world, has
been so great as to be incalculable.
A contemporary and acquaintance of Harvey was Robert Boyle, one of the
most important of the early scientific investigators, who was an avowed
disciple of Bacon, and followed his methods with conscientious care.
His work covered a large field, but it was concerned mostly with the
action of gases. He is best known by "Boyle's Law," which is usually
expressed as follows: "When the volume of a mass of gas is changed,
keeping the temperature constant, the pressure varies inversely as the
volume; or the product of the pressure by the volume remains constant."
While it has been found that this law is not absolutely true with all
gases at all temperatures and pressures, its departure from accuracy
are very small, and these are now definitely known. With certain
tabulated corrections, this law is the basis on which most of the
calculations for steam engines, air engines and gas engines are made.
It is usually expressed by the formula
p v = p´ v´ = constant.
Boyle is said to have "discovered" this law, and Harvey is said to have
"discovered" the circulation of the blood. Doubtless they did: but if
they had done no more than "discover" these things, no one else would
have been the wiser, and the world would have been no richer. What
these two men did that made us wiser and the world richer, was to make
inventions of definite character, and give them to the world in such
manageable forms, that "persons skilled in the art can make and use
them."
In 1620, the spirit thermometer, as we know it now, was invented by
Drebel. It is by some ascribed to Galileo. An interesting controversy
has been waged as to which was actually the inventor. The facts seem to
be that Galileo did invent a thermometer in which the height of water
in a glass tube indicated approximately the temperature. The tube was
long and ended in a bulb at the top. The bulb being warmed with the
hand of Galileo, and the open lower end of the tube being immersed in
water, and then the warmth of the hand removed, water rose in the tube
to a height depending on the warmth of the air in the bulb. The height
of the water therefore varied _inversely_ as the temperature. The
defect of the instrument was that it was a barometer as much as it was
a thermometer; because the varying pressure of the atmosphere caused
the water to rise and fall accordingly, and thus falsify the thermal
indications. Drebel realized this, and closed both ends of the tube.
Thus Galileo came very near to inventing both the thermometer and the
barometer, but yet invented neither! It seems incredible that he should
have failed to invent the barometer, having come so near it; for he had
been engaged for a long period in investigating the weight of air, and
finally had succeeded in ascertaining it. The barometer was invented
or rather discovered by Galileo's successor, Torricelli, in 1645.
Torricelli, in investigating the action of suction pumps, constructed
what now we call a barometer; but it was not until _after_ he had
constructed it that he realized that the height of mercury in his tube
indicated the pressure of the air outside. Seventy-five years later,
Fahrenheit made a great improvement in the thermometer by substituting
mercury for spirits.
Meanwhile, Otto von Guericke, following in the footsteps of Galileo and
Torricelli, had invented the air-pump, by means of which he succeeded
in getting a fairly perfect vacuum in a glass receiver. This seems to
have been an invention of the most clear-cut kind, resulting from an
idea that occurred to Guericke that he seized upon promptly and put to
work to serve mankind. Its influence in giving impetus to the science
and art of pneumatics, and the influence of pneumatics on the progress
of civilization, are too obvious to need more than to be pointed out.
The invention of Guericke is a simple and clear illustration of the
"power of an idea"; an illustration of seed falling on good ground and
bringing forth fruit an hundred fold.
One of the greatest inventors that ever lived was Isaac Newton, who
lived from 1642 till 1728. Even as a child he busied himself with
contriving and constructing mechanical appliances, mostly toys. As
a young man he occupied himself mostly with studies in mathematics
and experiments in physics, especially optics. In 1671 he invented
a special form of the reflecting telescope, called after him the
Newtonian telescope. He made many experiments in optics, in consequence
of which he discovered and announced that white light consists of seven
colors, having different degrees of refrangibility. The influence of
this discovery on the advancement of learning since that time, it
is unnecessary to point out; but we cannot realize too clearly that
without it much of the most important progress in optics since that
time would have been impossible.
The invention by reason of which Newton is most generally known is his
theory or law of gravitation, which he announced in his _Principia_,
published in 1686. In 1609, Kepler had announced his famous laws, that
reads:
"1. The orbits of planets are ellipses having the sun at one
focus.
"2. The area swept over per hour by the radius joining sun and
planet is the same in all parts of the planet's orbit.
"3. The squares of the periodic times of the planets are
proportional to the cubes of their mean distances from the
sun."
Newton showed from the laws of mechanics which he had discovered that,
assuming the first two laws of Kepler to be true, each planet must
always be subject to a force directing it toward the sun, that varies
inversely as the square of its distance from the sun: otherwise, it
would fly away from the sun or toward it. From this, Newton inferred
that all masses, great and small, attract each other with a force
proportional to their masses, and inversely proportional to the square
of the distance between them, and invented what is now called the law
of universal gravitation.
Another invention of possibly equal value, also published in his
_Principia_, but not so generally known, is his three laws of motion.
These are
"1. Every body continues in its state of rest, or of moving
with constant velocity in a straight line, unless acted
upon by some external force.
"2. Change of momentum is proportional to the force and to the
time during which it acts, and is in the same direction as
the force.
"3. To every action there is an equal and contrary re-action."
It is probably impossible for any human mind to conceive any invention
of a higher order of originality than either of these two, or to
construct any invention more concrete and useful. Certainly no more
brilliant inventions have ever yet been made. These two wonderful
products of Newton's genius underlie the whole structure of modern
astronomy and modern mechanics. The sciences of modern astronomy and
modern mechanics could not exist without them, and would not now exist
unless Newton (or someone else) had invented them.
It may be pointed out that Newton's conception of our solar system is
that of a machine in rapid motion, of which the sun and the planets are
the principal parts.
Another important invention ascribed to Newton is that of the sextant,
a small and easily handled instrument, used ever since in ships for
purposes of navigation; but whether he should receive the entire credit
for this invention seems quite doubtful; for another astronomer, Robert
Hooke, is credited by some with the original suggestion, and John
Hadley, still another astronomer, with having adapted it to practical
sea use. Numerous other scientific inventions, however, that have
formed the basis of much of the scientific work of later experimenters
and inventors are clearly to be credited to Newton. Among these, his
formula for the velocity of a wave of compression, his color-wheel,
and his simple apparatus known as "Newton's rings," by which can be
measured the wave lengths of light of different colors, are possibly
the most important.
In approximate coincidence with the Renaissance movement and the
accompanying awakening of the intellect of Europe, there began a
conflict between the sovereigns and the Pope. The Popes had gradually
acquired great power, because of their prestige as the successors of
St. Peter, to whom it was declared our Savior had given the keys of
heaven. Coincidentally, the multitudinous barons had gradually built
up the Feudal System. This was a loose-jointed contrivance, under
which Europe was virtually divided into little geographical sections,
ruled over by hereditary feudal lords, who in each country owed
allegiance to a sovereign. By reason of the slowness and uncertainty
of transportation and communication, the various feudal lords were
extremely independent, and each one did substantially as he willed in
his little domain.
The situation was a miserable one for every person, except the Pope,
the sovereigns, the feudal lords and their hangers-on; not only
because of the various petty tyrannies, but because of the continual
little wars and the general absence of good government. Gradually,
the sovereigns got more and more power (except in England) and the
conditions improved so much that the people realized that it was better
to be ruled by one king, or emperor, than by a multitude of barons. The
sovereigns finally acquired so much power that they dared to oppose the
Pope in many of his aggressions; but no very important situations were
developed until the Reformation caused the existence of protestant or
heretic sovereigns, and the occasional excommunication of one of them
by the Pope, with its attendant exhortation to his subjects to take
up arms against him. To meet this situation, the theory of the Divine
Right of Kings was invented.
This was a very important invention; for it offset the Divine authority
of the Pope as Pope, and gave a theme for the bishops and priests in
their discourses to the people, and a slogan for the soldiers. It was
extremely successful for three centuries, and its influence was in the
main beneficent. It worked for the establishment of stable governments
and great nations, tended to prevent the excessive domination of
a religious organization, and, by recognizing the fact that every
sovereign's power comes from the Almighty, it suggested the sovereign's
responsibility to Him. At first this suggestion evidently bore little
fruit; for the seventeenth and eighteenth centuries were characterized
by general oppression of the people, and filled with dynastic wars,
waged merely in behalf of monarchical ambitions. But gradually the
kings and the peoples came to realize the duties of sovereigns, as well
as their privileges and powers. Gradually then, the view came to be
held that kings were bound to exercise their power for the benefit of
their people.
Even the doctrine of the Divine Right of Kings, now condemned and
obsolete, had a great influence and a good influence during the time it
was in vogue; and it supplies a clear illustration of the power of a
good idea, skillfully developed, to fulfill a given purpose, so long as
its existence is necessary.
Most men have a considerable amount of energy, but do not know what to
do with it. Children are in the same category, except that toys have
been invented for them, and parents give these toys to their children.
Without toys, children find the days very long, and parents find their
children very trying. The usefulness of toys seems to be mainly, not so
much in giving children pleasure directly, as in supplying an outlet
for their energies, both physical and mental. For what greater pleasure
is there than in expending one's natural energies under pleasant
conditions?
Possibly, all the work that men have done in building up civilization
is like the work that children have done with building blocks.
Certainly there are many points of similarity. The mental efforts are
similar; and, so far as we can see, the results are similar also.
Toy temples have been built of building blocks, and then have been
destroyed. Civilizations also have been built and then destroyed. And
in the case of both the building blocks and the civilizations, the
pleasure seems to come, not from the result achieved, but from an
enjoyable expenditure of energy in achieving it. In both cases it has
been the inventors who have pointed out the ways in which to expend the
energy, and achieve the results.