securely bind the grain as cut. The scarcity and high price of labor
renders such a machine an absolute necessity. The efforts to supply this
great want have been numerous, but with no flattering success so far as
I am able to learn, except the machine invented by a citizen of this
place, which has already made its mark by demonstrating that automatic
machinery can and does bind the grain as fast as cut. The machine I
speak of is yet in a chrysalis state, so to speak, but it has been
worked two years in the field, the last season without missing a bundle,
though not without the usual difficulties of all new machines in respect
to the workings of some parts--too weak, etc. It is believed that
the coming harvest will witness its triumphant success. If so, the
production of our staple cereal will be greatly cheapened. I shall
be glad to renew "old acquaintance," by a more detailed statement
hereafter.
I send enclosed the pay for another year of the SCIENTIFIC AMERICAN,
which I can no more do without than my accustomed dinner.
C.
Madison, Wis.
* * * * *
Economical Steam Engine.
Messrs. Editors:--Permit me now to make a few remarks in regard to an
article on page 844, last volume of the SCIENTIFIC AMERICAN, entitled
"Which is the Most Economical Steam Engine?" The principles laid down in
that article, I think are correct.
I run a saw-mill with an engine which fills those conditions nearer than
I ever saw, and I would like to give your readers a brief description
of it. The cylinder is 10-inch bore, and 14-inch stroke; steam chest
extends enough beyond the ends of the cylinder so that the steam travels
only 2½ inches, the shortest distance possible, after leaving the valve
before it reaches the piston-head, and the space between the piston-head
and cylinder-head is only one-fourth of an inch, the bolt heads
being counter-sunk until even. Other things about this engine are in
proportion. With this engine attached to a direct acting circular mill,
I can saw 2,000 feet of hard-wood inch boards in one hour.
If any of your readers can beat this, I would like to hear from them.
JOHN CARNES.
* * * * *
Friction and Percussion.
Messrs. Editors:--In reply to "Spectrum," page 358, of last volume,
I will be brief. In his third paragraph he claims that he has merely
_suggested_ that friction and percussion may often be one and the same
thing; and immediately claims that in the case of the polished button
rubbing a planed pine board, the force which overcomes and levels the
undulations of the wood, is percussion, and that percussion is also the
cause of the heat; the microscopic hills and hollows on the shining
brass button skipping and jumping along the pine, produces little
infinitesimal bumpings, and so pound out the heat. This _little_ theory
should be known to the homeopaths--they could illustrate infinitesimal
quantities by it!
"Spectrum" treats my hammered horsenail illustration shabbily. After
indirectly acknowledging that there is a point where hammering will
no longer produce heat, he puts it on the grindstone, subjects it to
friction, and when it burns his fingers, throws his hat in the air and
shouts "Hurrah for _percussion!_" We agree perfectly, except that he
calls hammering, _condensation_; calls friction, _percussion_; and drops
friction from the mechanical dictionary altogether.
A railway car axle often heats and sets fire to the packing, when the
journal is smooth as polished glass; but I never heard of those parts
of the car which are constantly undergoing percussion, even getting
uncomfortably warm. The natives of the South Pacific produce fire by
rubbing pieces of dry wood together, but I never heard of their rapping
sticks for the same purpose. I have seen a new, sharp knife made hot
enough to raise a blister, whittling a clean dry stick of pine, and
I would like to have "Spectrum" tell us, if in all the above cases
percussion is the cause of the evolution of of heat, and what is
friction doing in the mean time.
New Albany, Ind.
C.C.H.
* * * * *
Oiling a Preservative of Brown Stone.
Messrs. Editors:--I have read the article entitled, "What is to Become
of our Brown Stone Fronts," and have waited to see what others have to
say. But with so much at stake, no body seems to know what to do or say.
Being a practical painter, it has been my lot to oil some of the best
fronts in New York, namely corner of 23d Street and 5th Avenue, No. 2,
West 23rd Street, also No. 1, West 30th Street; also the residence of
E.S. Higgins, the carpet manufacturer, done by other journeymen.
They were very dark in color for a few weeks, but now after two years,
they are bleached almost as light as they were at first.
These fronts were cleaned whenever necessary, and then oiled with fresh
raw linseed oil from the press, put on pretty much as carefully as in
ordinary varnish work. No second coat or lapping over of the oil. All
was put on at once that it would take without running down in streams.
The result: the oil penetrates into good dry stone probably 1½ inches,
making the stone hard and flinty, as any stone cutter will soon find out
if he tries to trim it.
It keeps the damp and therefore the frost out of the stone, as will be
seen any foggy day, the damp running down in streams on the oiled stone,
and the unoiled stone absorbing the dampness. It is therefore necessary
to oil during dry weather.
The oil is especially beneficial to balustrades and carvings, as they
are generally got out of soft stone. It is also beneficial underneath
balconies and porches, as the sun never has a chance to dry the stone in
such situations before the frost flakes it.
This I send in part payment for the great deal I have learned from your
paper.
T.H. Rilley
New York City.
* * * * *
Interesting Correspondence from China.
Messrs. Editors:--Your paper seems to increase in interest. I brought
the back volumes from Madras to Pekin, and am glad to refer to them here
where I must depend upon myself.
I have been building and repairing premises since I came here last year.
I find the carpenters and masons are very much delighted with our tools,
especially our saws, planes, borers, vise, and hammers. Our lathe is a
wonder. They use only the ancient spindle turned backwards and forwards
by a treadle or by the left hand while the right guides the chisel or
turning-tool, which cuts only half the time. They use only the turning
saw, which often fails them because it cannot be used in splitting wide
boards in the middle, and in many other places. They are great sawyers,
however. They stand heavy pine spars on end, if rather short, say 8
feet, the common length of many intended for making coffins, and cut
them up into three-eighths or half-inch stuff with great patience. A
longer one they will lean over and prop up, raising it towards the
perpendicular as they advance. They must have some hard jobs. I have
just measured a poplar plank in front of a coffin manufactory, which I
found to be 5 ft. 3 in. at the butt, 3 ft. 10 in. at the top, 8 feet
long, and about 8 inches thick. For a crosscut saw they rig one like
our wood-saw. I am sure it would deeply interest you to make a visit to
Pekin and see how this ancient, patient, and industrious people do their
work. It is truly painful to see how much time they spend in making
the simplest tool for want of at least a few labor-saving appliances.
Doubtless you have their tools on show in New York. They are to me an
interesting study, though I have been long familiar with the rude tools
of the Hindoos. It is constantly suggested to me that we must have got
many hints from the Chinese, or else indeed they have taken hints from
the West; or again, which is perhaps the true solution, implements like
words have a common origin. I should think from what I have observed in
a short time, that the Chinese resemble the Europeans in their tools
more than the Hindoos--a thing I did not at all anticipate. A clever man
could write you an interesting chapter on the ways of the Pekinese,
the Chinese Manchus, Mongols, and the rest mixed together, though the
Chinese are confessedly the workers in wood, iron, and everything else.
The Manchus are mostly hangers on of the government, living mainly upon
a miserable monthly stipend.
The reading of your unequaled journal makes me interested in you as if
you were personal friends, and so I have run away with these pointless
remarks. I am sure you will excuse me, and not wonder that one wishes to
breathe now and then.
I was an old subscriber in Madras, and hope to be till I can read no
longer. My son, who perished at Andersonville, was a subscriber to the
SCIENTIFIC AMERICAN till the day of his capture by Mosby.
Pekin, China.
P.R. Hunt.
* * * * *
Communication Between Deaf and Blind Mutes.
Messrs. Editors:--In a recent number of the SCIENTIFIC AMERICAN I notice
an ingenious method of teaching deaf and dumb persons to converse in
the dark, which is also applicable to blind mutes, and it brings to my
recollection a method which was in use among the "telegraph boys" some
years ago when I was one of them. Sometimes when we were visiting and
asked to communicate to a "brother chip," anything that it was not
advisable for the persons around us to know, a slight tap-tapping on the
table or chair would draw the attention of the party we asked to talk
to, and then by his watching the forefinger of the writer, if across the
room, or if near enough, by placing the hand of the writer carelessly
on the shoulder of the party we desired to communicate with, the
communication was written out in the telegraph alphabet or by taking
hold of his hand and writing upon the finger.
I think this method will be found much less complicated, if not quite as
rapid, as the method with both hands, and much more convenient, as it is
only necessary to have hold of one hand of the person communicated with,
and is more rapid than writing with a pen.
For the benefit of those not acquainted with the telegraph alphabet, I
give it:
A B C D E F G H I
.- -... ... -.. . .-. --. .... ..
J K L M N O P Q
-.-. -.- --- -- -. . . ..... ..-.
R S T U V W X Y
. .. ... - ..- ...- .-- ..-. .. ..
Z
... .
The uninitiated will observe that O differs from I in the distance
between the dots, made thus: I by two quick strokes of the forefinger; O
by one quick stroke, slight pause, and another quick stroke; the dashes
are made by holding the finger down for a short space: thus SCIENTIFIC
AMERICAN would be written:
S C I E N T I F I C
... .. . .. . -. - .. .-. .. .. .
A M E R I C A N
.- -- . . .. .. .. . .- -.
In a very short time any one can learn to read by the sight or by the
touch. Anything which can add to the pleasure or comfort of these
unfortunates is of importance.
MAGNET
[Nothing can compensate for want of rapidity in a language designed for
colloquy. Although our correspondent found the Morse telegraph alphabet
a resource on occasion, he would scarcely be content to use it, and it
only for life, even if emancipation from it involved months of labor.
The motions required to spell SCIENTIFIC AMERICAN by the telegraph
alphabet are thirty-nine, but as the short dashes occupy the time of two
dots for each dash, and there are eight of these, eight more ought to be
counted in a comparison of it with an alphabet composed wholly of dots,
this would make forty-seven. To spell the same words in full by the mute
alphabet referred to would require only twenty-three motions. A still
greater disparity in rate would, we think, be found in an entire
colloquial sentence. Thus the sentence "Hand me an apple" would require,
by the mute alphabet, the time of fourteen dots, while with the
telegraph alphabet it would require the time of thirty-nine.--Eds.]
* * * * *
Cheap Cotton Press Wanted.
Messrs. Munn & Co.:--Please give us any information of cheap
cotton-presses, such as small neighborhoods, or single planters, in the
South could own. In particular, a press that will put 40 pounds cotton
into each cubic foot. We want cotton better handled, and to that end may
want small bales, say 150 pounds each. But these must be put into three
or four cubic feet, or they will cost too much for covering, ties, etc.
Perhaps you can furnish us with a wood-cut of some, or several, presses
worked by hand, or by horse-power, that will do good service, not cost
too much, be simple in operation, not require too much power, and be
effective as above. It may be for the interest of some of your clients
or correspondents to give us the facts, as we shall put them into
a report for circulation amongst the entire cotton interest of the
country.
Yours very truly,
WALTER WELLS, _Sec'y_.
National Association of Cotton Manufacturers and Planters, No. 11,
Pemberton Square, Boston, Mass.
* * * * *
A Singular Freak of a Magnet.
Messrs. Editors:--In my library hangs a powerful horseshoe magnet which
has a keeper and a weight attached of about three ounces. This weight
is sustained firmly by the attracting power of the magnet, and is not
easily shaken off by any oscillating motion, yet through some (to me)
unknown cause during each of the last ten nights the magnet has lost its
power, and the keeper and weight lie in the morning on the bottom of the
case where the magnet has hung for many years without a like occurrence,
except once on the occasion of a severe shock of an earthquake which
took place December 17, 1867.
There is no possible way for this magnet to be disturbed except by the
electric current; then why should its power thus return without the aid
of a battery or keeper? Will some one explain?
FLOYD HAMBLIN.
Madrid Springs, N.Y.
* * * * *
Speaking makes the ready man, writing the correct man, and reading the
full man.
* * * * *
PRESERVATION OF IRON.
BY PROF. HENRY E. COLTON.
"What is wanted is something equally applicable to large or small pieces
of iron, and which will answer to ward off the attacks not only of the
common atmospheric oxygen, but also remain unaffected by acids or salt
waters."
The above from a late number of the SCIENTIFIC AMERICAN states not only
the writer's ideas but also one of the greatest wants of the age. Iron
is daily being put to more and more varied uses. On land the great
question is what will prevent rust; on water, what will prevent rust and
fouling of bottoms of iron vessels. We will briefly summarize the many
patents granted for this purpose.
Eight are for sheathing of various kinds put on in varied modes. The
most practicable of these is a system prepared by Daft. Most iron
vessels are now constructed by every other plate lapping the edges of
the one between. He proposes, instead of having the plates all the same
width, to have one wide and one very narrow plate. This would leave a
trough between the two wide plates of the depth of the thickness of the
plates. He proposes to force into this trough very tightly pieces of
teak, and to the teak, thus embedded, he nails a sheathing of zinc. The
zinc is kept clean by slowly wearing away of its surface from action by
contact with the iron and salt water.
There are four patents, in which various, so-called, non-conducting
coats are put on the iron, and copper pigment in some form put on over
them. These have been specially condemned in England, as no matter how
good the non-conducting substance--and many are so only in name--it will
become rubbed off at some points, and there the bottom will be eaten
both by salt water and action of copper.
Coal tar and asphaltum are the subjects of patents in various forms.
One patent claims rubber or gutta-percha dissolved in linseed oil as a
vehicle in which to grind the pigment; another the same dissolved in
naphtha or bisulphide of carbon as a pigment; another hard rubber,
ground.
Enameling with different materials is proposed by some, while one
proposes to glaze the bottoms so that barnacles and grass would find a
slippery foothold.
Combinations of tallow, resin, and tar--mineral and pine--are patented
mostly to use over other paints.
Coal tar, sulphur, lime, and tallow, are the subject of one patent;
guano, red lead, and oil of another; while sulphur and silica are
claimed by a third.
Paints containing mercury, arsenic, and even strychnine, are the
subjects of several patents. A mixture of coal tar and mercurial
ointment of one.
Galvanism is proposed to be used in various ways--strips of copper and
zinc, or by galvanizing the plates before use. Black lead finds a place
in many compositions.
One patent, by a complicated process, effects a union of metallic zinc
and iron; this, granulated and ground fine, then mixed with red lead
and oil, makes the paint. It is said to be the best of all the patented
stuffs.
It is astonishing how many use oils derived from coal, peat, or resin,
and tars of the same.
There are about fifty patents for this object and with all of them
before their eyes, the British Society for the Advancement of Art still
hold the $5,000 reward for a pigment or covering which will perfectly
protect from rust and fouling. However they may puff their products for
selling, no one has the temerity to claim that they deserve the reward.
We think it would be difficult to find so many expedients ever before
adopted for the accomplishment of any one object. These are all English
patents, England having necessarily been obliged to use iron for vessels
from its cheapness as well as its consequent first introduction there.
In the United States no patents worth mentioning have been granted.
The first requisites for a pigment or coating for iron are, that it
should not contain any copper--the corrosive action of that metal on
iron being intense. Then if for work exposed to air it should form
such a coating as to be impervious to that gaseous fluid, and be
so constituted chemically as not to be oxidizable by it; if under
water--especially sea water--to be impermeable to moisture, so elastic
as not to crack, so insoluble as not to chloridize; to form a perfect,
apparently hard, coating: and yet wear just enough to keep off
incrustation, barnacles, or growth of grass. In fact, this slow wearing
away is the only preventive of fouling in iron vessels. Wooden bottoms
may be poisoned by solutions of copper--and that metal has no superior
for such uses, especially when it is combined in mixture with mineral
or resinous tars and spirits--these compounds, however, are not only
useless on iron bottoms, but also injurious. What then is _the_
substance: 1st. One of the oxides of lead (red lead). 2d. The purest
oxide of iron to be found. If properly made these articles can be
carried to no higher state of oxidation, and respectively, as to order
named, they have no superiors for body and durability. By preference,
1st, red lead, either out of or under water; 2d, Prince's oxide of iron
only, out of water. The color of these paints--the first red, the latter
brown, may be hidden by a coat of white or tinted color. If there were
to be had in combination as a white paint, an oxide of lead and an oxide
of zinc, it would be immensely superior to either, but that such has not
been produced is rather the fault of carelessness than of possibility.
Zinc protects iron with great effect, but it is too rapidly worn in the
effort to be of lasting value. Hence the great desideratum, the yet to
be, the coming pigment is a white oxide of lead or a combined white
oxide of lead and white oxide of zinc, without sulphates or chlorides.
Those materials answer very well for work exposed to atmospheric air,
and perhaps nothing will ever be found better; but a different need is
that for salt water. No mere protector of the iron from rust can be
found superior to pure red lead and linseed oil. We have seen a natural
combination of zinc, lead, and iron, which, in our experience, ranks
next; but the zinc is acted on by the chloride of sodium, and wears away
too much of the material. Red lead, however, while covering the iron
perfectly and effectually preventing rust, and also having but little
disposition to chloridize, when it does, will foul both with grass and
barnacles. Hence, the first desideratum being obtained, how shall we
accomplish the other. The prevention of fouling may be accomplished in
two ways: First, cover the vessel's bottom with two or even three coats
of red lead, and give each time to dry hard. Then melt in an iron pot a
mixture of two parts beeswax, two parts tallow, and one part pine resin;
mix thoroughly, and apply hot one or two coats. This mixture may be
tinted with vermilion or chrome green. It is not necessary to use any
poisonous substance, as it is only by its softness and gradual wear
that it is kept clean. Second, mix red lead and granular metallic zinc,
ground fine, or such a mineral as we have mentioned--crystalline and
granular in its character. Put on two or three coats, and allow each to
set--they will never dry hard. The zinc will slowly wear off, keeping
the whole surface clean, while there will be left enough coating of the
lead to preserve the iron from rust. The oil I would urge for these
pigments is linseed--as little boiled as possible, to be thinned with
spirits of turpentine. There seems to have been a mania for mixtures of
tar and resins, their spirits and oils; my experience fails to show me
any advantage for them on an iron bottom. They have neither elasticity
nor durability, while linseed oil has both in a pre-eminent degree, and
is no more likely to foul than they, when in a combination that does
not dry hard. Besides they are difficult to grind, inconvenient to
transport, and offensive to use.
Perhaps we have not, in the opinion of some, answered the want expressed
in the first paragraph. No pigment with the requisites of durability and
cheapness will resist the attacks of strong acids on iron. The first we
have mentioned will--all such as may float in our air from factories or
chemical works. Chemically it is converted by nitric acid and chlorine
into an insoluble substance--plumbic acid or the cyanide of lead. An
experience of more than three years, with almost unlimited means at our
command for experiment, demonstrates to us that we have indicated
the means of filling the other requisites asked for. It may be that
something new will be discovered, but we doubt it. Let any one tread the
road we have trod, investigate and experiment where and as much as we
have, and, if that place is, where we have not, and their experience
will be the same as ours.
* * * * *
THE BANANAS AND PLANTAINS OF THE TROPICS.
[For the Scientific American.]
Poets have celebrated the banana plant for its beauty, its luxuriance,
the majesty of its leaves, and the delicacy of its fruit; but never have
they sufficiently praised the utility of this tropical product.
Those who have never lived in southern countries are unable to fully
appreciate its value. Some look even with indifference upon the gigantic
clusters of this fruit, as they are unloaded from the steamers and
sailing vessels; and yet they deserve special attention and admiration,
for they are to the inhabitants of the torrid zone, what bread and
potatoes are to those of the north temperate zone.
The banana tree is one of the most striking illustrations of tropical
fertility and exuberance. A plant, which in a northern climate, would
require many years to gain strength and size, is there the production of
ten or twelve months. The native of the South plants a few grains, taken
from an old tree, in a moist and sandy soil, along some river or lake;
they develop with the greatest rapidity, and at the end of ten months
the first crop may be gathered, though the cluster and bananas are yet
small; but the following year one cluster alone will weigh some sixty or
more pounds. Even in the South they are always cut down when green, as
they lose much of their flavor when left to ripen or soften on the tree.
The trunk of the tree, if it may be so called, and which grows to a
hight of some fifteen feet, is formed only by the fleshy part of the
large leaves, some of which attain a length of eighteen feet, and are
two and a half feet in width. While from an upper sprout you perceive
the large yellow flowers, or already formed fruits, you see underneath a
cluster, which is bending the tree by its weight.