Scientific American, Vol.22, No. 1, January 1, 1870 by Various
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Various >> Scientific American, Vol.22, No. 1, January 1, 1870
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[Illustration]
"The block is made on the differential principle. The lifting chain is
passed over two sheaves, each of which is geared internally, the one
having one or more teeth in excess of the other. Revolving around these
internal teeth is a pinion, actuated by an eccentric, which is keyed on
to a shaft passing through the center of the block, with a bearing at
each end in the outside frame of the block. At one end of this shaft
is a wheel with an endless hand chain passing over it; this gives the
motion to the eccentric shaft. The teeth of the internal pinion are
broad enough to gear into the teeth of both the sheaves, but as there is
more teeth in one than in the other, they (the teeth) are not exactly
opposite each other, and therefore will not admit the teeth of the
revolving pinion without moving; but the tooth of the pinion, acting as
a wedge, and entering with great power, pushes the one tooth forward and
the other tooth back; and this continually occurring, a continual rotary
motion is given to the sheaves, in opposite directions, with a power
which is proportioned to the number of the teeth, the throw of
eccentric, and the leverage gained by the diameter of the hand wheel.
The lifting chain is passed over the one sheave, then down, and up over
the other, the two ends being attached to a powerful cross bar, to which
is connected the lifting hook. By this means the weight is distributed
over the two sheaves and the two parts of the chain, increasing the
safety and diminishing the friction of the block.
"The blocks are very simple in construction, and are not at all liable
to get out of order; the construction being such that the weight cannot
run down, though the men lifting let go the chain. They hang quite plumb
when in action, and the men are able to stand clear away from under the
load, as the hand-wheel chain can be worked at any angle."
* * * * *
Plants In Sleeping Rooms.
The following from the able pen of Dr. J.C. Draper, in the January
number of the _Galaxy_, will answer some inquiries lately received on
the subject, and is a brief, but clear exposition of the injurious
effects of plants in sleeping apartments:
"Though the air is dependent for the renewal of its oxygen on the action
of the green leaves of plants, it must not be forgotten that it is only
in the presence and under the stimulus of light that these organisms
decompose carbonic acid. All plants, irrespective of their kind or
nature, absorb oxygen and exhale carbonic acid in the dark. The quantity
of noxious gas thus eliminated is, however, exceedingly small when
compared with the oxygen thrown out during the day. When they are
flowering, plants exhale carbonic acid in considerable quantity, and at
the same time evolve heat. In this condition, therefore, they resemble
animals as regards their relation to the air; and a number of plants
placed in a room would, under these circumstances, tend to vitiate the
air.
"While the phanerogamia, or flowering plants, depend on the air almost
entirely for their supply of carbon, and are busy during the day in
restoring to it the oxygen that has been removed by animals, many of the
inferior cryptogamia, as the fungi and parasitic plants, obtain their
nourishment from material that has already been organized. They do not
absorb carbonic acid, but, on the contrary, they act like animals,
absorbing oxygen and exhaling carbonic acid at all times. It is,
therefore, evident that their presence in a room cannot be productive of
good results.
"Aside from the highly deleterious action that plants may exert on the
atmosphere of a sleeping room, by increasing the proportion of carbonic
acid during the night, there is another and more important objection to
be urged against their presence in such apartments. Like animals, they
exhale peculiar volatile organic principles, which in many instances
render the air unfit for the purposes of respiration. Even in the days
of Andronicus this fact was recognized, for he says, in speaking of
Arabia Felix, that 'by reason of myrrh, frankincense, and hot spices
there growing, the air was so obnoxious to their brains, that the
very inhabitants at some times cannot avoid its influence.' What the
influence on the brains of the inhabitants may have been does not at
present interest us: we have only quoted the statement to show that long
ago the emanations from plants were regarded as having an influence on
the condition of the air; and, in view of our present ignorance, it
would be wise to banish them from our sleeping apartments, at least
until we are better informed regarding their true properties."
* * * * *
PATENT OFFICE ILLUSTRATIONS.--We are indebted to Messrs. Jewett &
Chandler, of Buffalo, N.Y., for advance sheets of the illustrations
designed to accompany the Report of the Commissioner of Patents for the
year 1868. We have frequently had occasion to commend the skill and
fidelity of these illustrations. They are most admirably done, and the
value of our Patent Office Reports is much enhanced thereby. In fact
without these illustrations the reports would be of little value.
* * * * *
Improved Treadle Motion.
It is well known that the ordinary means employed to propel light
machinery by the foot are fatiguing in the extreme and although the best
of these is the rock shaft with foot pieces, employed almost universally
in modern sewing machines, this requires the operator to sit bolt
upright, a position very trying to the back, and one which has been
shown to be productive of weakness and even permanent disease.
The device shown in the engraving employs only the swinging motion of
the leg to generate the required power.
[Illustration: GOODES' IMPROVED TREADLE MOTION.]
A pendulum, A, is pivoted to the underside of the table and carries a
heavy disk, B. To the central pivot of B is attached a foot piece, C.
The bottom of B is slotted, and through the slot passes a stationary
rod, D, which holds the bottom of the disk from vibrating while it
causes the upper part to reciprocate with the swinging of A.
To the upper part of B is pivoted a pitman which actuates the crank as
shown.
In operation the foot is placed upon the foot piece, and a swinging
motion is imparted by it to the pendulum, which is ultimately converted
into rotary motion by the crank as described. The heavy disk, B, gives
steadiness to the motion, and acts in concert with the fly wheel on the
crank shaft for this purpose; but it is not essential that this part of
the device should be a disk; any equivalent may be substituted for the
same purpose.
Patented, through the Scientific American Patent Agency, Oct, 26, 1869,
by E. A. Goodes For further information address Philadelphia Patent and
Novelty Co., 717 Spring Garden street, Philadelphia, Pa.
* * * * *
Improved Method of Catching Curculios.
This is a novel and curious invention, made by Dr. Hull, of Alton, Ill.,
for the purpose of jarring off and catching the curculio from trees
infested by this destructive insect. It is a barrow, with arms and
braces covered with cloth, and having on one side a slot, which admits
the stem of the tree. The curculio catcher, or machine, is run against
the tree three or four times, with sufficient force to impart a jarring
motion to all its parts. The operator then backs far enough to bring the
machine to the center of the space between the rows, turns round, and in
like manner butts the tree in the opposite row. In this way a man may
operate on three hundred trees per hour.
A bag and a broom are carried by the operator by which the insects are
swept from the cloth and consigned to destruction.
[Illustration: CURCULIO CATCHER.]
* * * * *
Remains of a Megatherium in Ohio.
The Columbus _State Journal_, of Dec. 6, says "there is now on
exhibition at the rooms of the State Board of Agriculture, or
headquarters of the Geological Corps, a section of the femur or thigh
bone of an animal of the mastodon species, the fossilized remains of
which were recently discovered in Union county. These remains were found
in a drift formation about three feet below the surface, and are similar
to the remains of the Megatherium found in other parts of the State.
Arrangements were made by Mr. Klippart, of the Geological Corps, to
have the skeleton or the parts thereof removed with proper care. Before
excavations had proceeded far bad weather set in, and work has been
abandoned. The section of the femur, upper part, with socket ball, is
about twenty inches in length, or about half the length of the thigh
bone. This would make the aggregate length of the bones of the leg about
ten feet. The ball is twenty-two inches in circumference, and the bone
lower down, of course, much larger. From the part of the skeleton
secured, it is estimated that the hight of the animal was twelve and a
half feet, and the skeleton entire much larger than the specimen now in
the British Museum. As this particular species, or remains thereof, have
been found only in Ohio, this specimen has been named the _Megatharium
Ohioensis_. The animals lived, it is supposed, in the period immediately
preceding the human period, and were after the elephant type."
Exhuming operations will be resumed in the spring, and if the skeleton
is removed in good shape or a good state of preservation, it will be set
up in the Echo room at the Capitol, where the fossils collected by the
Geological Corps are now being arranged and stored.
* * * * *
Artificial Ivory.
A process for producing artificial ivory has been published in a German
journal. The inventor makes a solution of india-rubber in chloroform and
passes chlorine gas through it. After this, he heats the solution to
drive off any excess of chlorine, and also the solvent, whereupon he has
left behind a pasty mass with which it is only necessary to incorporate
sufficient precipitated carbonate of lime or sulphate of lead, or,
indeed, any other dense white powder, to obtain a material which may be
pressed into molds to form whatever articles may be desired. The details
of this process are obviously incomplete, and the success of it may be
doubted. Only good and well masticated rubber could be employed, and
even then a dilute solution must be made, and any earthy impurities
allowed to deposit. In the next place, we are doubtful of the bleaching
action of chlorine on rubber, and, moreover, chloroform is, under some
circumstances, decomposed by chlorine. Lastly, it is clear that, to
obtain a hard material at all resembling ivory, it would be necessary to
make a "hard cure," for which a considerable proportion of sulphur
would be required. The simple purification of india-rubber by means of
chloroform, would, however, furnish a mass of a very fair color.
* * * * *
An iron car made of cylindrical form is now used on the Bengal Railway,
for the carriage of cotton and other produce. It is much lighter and
safer than the ordinary car. We believe in iron cars.
* * * * *
ONE HUNDRED THOUSAND.--At the rate old subscribers are renewing, and new
ones coming in, there is a prospect that our ambition to increase the
circulation of this paper to one hundred thousand will be gratified.
* * * * *
AMERICAN AND ENGLISH RAILWAY PRACTICE CONTRASTED.
A paper on "American Locomotives and Rolling Stock," read before the
Institution of Civil Engineers, in England, with an abstract on the
discussion thereon, has been forwarded to us by the publishers, William
Clowes and Sons, Stamford street and Charing Cross, London.
We have seldom met with a pamphlet of greater interest and value. The
whole subject of American as contrasted with English railroad practice
is reviewed, and the differences which exist, with the necessities for
such differences ably discussed. Mr. Colburn shows these differences
to be external rather than fundamental, and traces many of the
peculiarities of American construction to the "initiative of English
engineers." The cause for the adoption and retention of these
peculiarities he attributes to "the necessities of a new country and the
comparative scarcity of capital," and thinks that but for these causes"
American railways and their rolling stock would have doubtless been
constructed, as in other countries, upon English models, and worked, in
most respects, upon English principles of management.
He reviews the origin and introduction of American features of railway
practice, and points out as the distinguishing feature of American
locomotives and rolling stock the bogie, or swiveling truck. "Keeping
in mind the distinguishing merits of the bogie, the other differences
between English and American locomotives are differences more of costume
and of toilet than of vital principles of construction."
The author attributes the origin of the greater subdivision of rolling
weight and consequent coupling of wheels on American roads to the
comparatively weak and imperfect permanent way, estimating the maximum
weight per wheel as being for many years four English tuns, while three
tuns he considers, as more than the average for each coupled wheel of
American locomotives.
To follow the author through the whole of his able paper, and the
discussion which it elicited, would occupy more of our space than we
can spare for the purpose. We will, however, give in the author's own
language, an account of an experiment conducted by him in 1855 on the
Erie Railroad.
"In the autumn of 1855, the author, at the request of Mr. (now
General) M'Callum, the manager of the Erie Railroad, took charge of an
experimental train, which he ran over the whole length of the line and
back, a total distance of nearly 900 miles. The same engine was employed
throughout the run, occupying in all nearly three weeks, making an
average for each week day of about 50 miles. The line is divided into
four divisions, varying considerably in respect of gradients, and the
utmost load the engine could draw was taken in both directions over each
division. The maximum inclinations were 1 in 88. The results of the
experiments were so voluminous, that it will be sufficient to detail
the particulars of what may be termed crucial tests of adhesion and
resistance to traction.
"The engine had four coupled wheels and a bogie, the total weight in
working trim being 291/2 tuns, of which 17-7/8 tuns rested on the coupled
wheels available for adhesion. The coupled wheels were 5 feet in
diameter; the outside cylinders were 17 inches in diameter, and the
stroke 24 inches. The safety valves were set to blow off at 130 lbs.,
and the steam, as observed by a Bourdon gage, was seldom allowed to
exceed that limit. No indicator diagrams were taken, nor was any measure
taken of the wood burnt, all that could be consumed by the engine, in
maintaining the requisite steam, being supplied. The tender, loaded,
weighed 181 tuns. The train drawn consisted of eight-wheel wagons fully
loaded with deals. The average weight of each wagon was 5 tuns 8 cwt. 3
qrs., and of each wagon with its load 15 tuns 5 cwt. 3 qrs. nearly. The
wagons had cast-iron chilled wheels, each 2 feet 6 inches in diameter,
with inside journals 3 7/8 inches in diameter, and 8 inches long. All
the wagons had been put in complete order, and the journals, fitted with
oil-tight boxes, were kept well oiled. The gage of the line was 6 feet.
The weather was most favorable, clear and dry, with the exception of a
single day of heavy rain.
"Upon about one hundred miles of the line, forming a portion of the
Susquehanna division, a train of one hundred wagons, weighing, with
engine and tender, 1,572 tuns was taken. The train was a few feet more
than half a mile in length.
"At one point it was stopped where the line commenced an ascent of 24
feet in four miles, averaging 1 in 880 up for the whole distance. There
were also long and easy curves upon this portion. The train was taken up
and purposely stopped on the second mile, to be sure of starting again
with no aid from momentum. The average speed was 5 miles an hour, and
neither was the pressure of steam increased nor sand used except in
starting from the stops purposely made. The engine, even were its full
boiler pressure of 130 lbs. maintained as effective pressure upon the
pistons throughout the whole length of their stroke, could not have
exerted a tractive force greater than (17 x 17 x 130 lbs. x 2 ft.)/ 5
ft = 15,028 lbs.; nor is it at all probable that the effective cylinder
pressure could have approached this limit by from 10 lbs. to 15 lbs. per
square inch. Supposing, however, for the sake of a reductio ad absurdum,
that the full boiler pressure had been maintained upon the pistons for
the whole length of their strokes, the adhesion of the coupled driving
wheels, not deducting the internal resistances of the engine, would have
been 15028/40050 3/8 of the weight upon them. In any case there was
a resistance of 4,011 lbs. due to gravity, and if even 120 lbs. mean
effective cylinder pressure be assumed, corresponding to a total
tractive force of 13,872 lbs., the quotient representing the rolling and
other resistances, exclusive of gravity, would be but 6.27 lbs. per tun
of the entire train; a resistance including all the internal resistances
of the engine, the resistance of the curves, easy although they were,
and the loss in accelerating and retarding the train in starting and
stopping. This estimate of resistance would correspond, at the observed
speed of 5 miles an hour (upwards of 3/4 of an hour having been consumed
on the 4 miles), to 185 indicated H.P., which, with the driving wheels,
making but 28 revolutions per minute, would be the utmost that an engine
with but 1,038 square feet of heating surface could be expected to
exert. This was the highest result observed during the three weeks'
trial, but one or two others are worthy of mention. On the Delaware
division of the same line, the train, of 1,572 tuns' weight, was run
over 5 consecutive miles of absolutely level line, at a mean rate of
9.23 miles an hour, and during the same day, over 5 other consecutive
miles of level at a mean rate of 9.7 miles per hour. On both levels
there were 141/2 chain curves of good length, and the speed, from 9 to 12
miles an hour, at which the train entered the respective levels, was not
quite regularly maintained throughout the half hour expended in running
over them. But if even 7 lbs. per tun of the total weight be taken as
the resistance at these speeds, the tractive force will be 11,004 lbs.,
which is more than one fourth the adhesion weight of 40,050 lbs. On
the next day, the same engine drew 30 wagons weighing 4661/2 tuns, or,
including engine and tender, 514 tuns nearly, up a gradient of 1 in
1171/2, three miles long, at a mean speed of 101/4 miles an hour. The
resistance due to gravity was 9,814 lbs., and supposing the other
resistance to traction to amount to no more than 7 lbs. per tun, the
total resistance would be 13,412 lbs., corresponding to a mean effective
cylinder pressure of 117 lbs. per square inch, and to a co-efficient of
adhesion of almost exactly one third.
"It is needless to repeat instances of much the same kind, as occurring
during the experiment referred to. The author is bound to say that they
were, no doubt, influenced by the favorable circumstances of weather,
and something is to be allowed also for the great length of train drawn,
very long trains having a less tractive resistance per tun on a level
than short ones, and something, possibly more than is commonly supposed,
may have been due to the use of oil-tight axle boxes, the saponaceous
compound known as 'railway grease' being nowhere in use on railways in
the States. It could not possibly be used, except in a congealed form,
in the severe American winters; and Messrs. Guebhard and Dieudonne's
experiments (_vide_ "De la resistance des trains et de la puissance des
machines." 8vo. Paris, 1868, p. 36) made in 1867, on the Eastern Railway
of France, showed a very considerable diminution in the resistance of
oil-boxed rolling stock as compared with that fitted with grease boxes.
But, weighed upon the other hand, are the facts, first, that the line
was of 6-feet gage, and, _pro tanto_, so much the worse for traction;
secondly, that the wheels were comparatively small, and the inside
journals of comparatively large diameter, the ratio of the former to the
latter being as 73/4 to 1, instead of 12 to 1 as on English lines. It is
difficult to believe that the length and steadiness of the double bogie
goods wagons, scarcely liable as they are to lateral vibrations, had not
something to do with the result, which is in some respects unique in the
history of railway traction. The result, although not absolutely showing
the real resistance to traction, nor the real adhesion of the engine,
presents this alternative; namely, that the resistance must have been
unusually small, or the adhesion unusually large."
In the discussion which followed some doubts were expressed as to the
accuracy of Mr. Colburn's conclusions, drawn from the experiments
described; but it was conceded by some who took part in the discussion
that some of the features of our practice might be advantageously copied
in England. For the most part, however, the opinion prevailed that the
features of our system, which are here regarded as almost indispensable,
could not be introduced into English practice with advantage.
* * * * *
BOILER COVERING.
BY C.M. O'HARA, C.E.
At the regular weekly meeting of the Polytechnic Association of the
American Institute, held on Thursday evening, the 25th ult., the subject
of boiler clothing was discussed at some length, but without any
decisive conclusion being arrived at respecting the most serviceable and
economical material for that purpose. It appeared from the testimony
adduced, that though there is a variety of substances in use, even those
which are practically acknowledged as being the most efficient are
far from coming up to the required standard of utility, and are
characterized by defects which are at once forced upon us by a little
close examination. Felt is an admirable non-conductor of heat, but owing
to its combustible nature it is quite unreliable when subject to the
heat of a high pressure of steam. A large fragment of this material
which had been taken off the boiler of a North River steamboat was
exhibited at the meeting, scorched and charred as if it had been exposed
to the direct action of fire. For these reasons felt covering is,
generally speaking, confined to boilers in which a comparatively low
pressure of steam is maintained. But even under the most favorable
circumstances of actual wear its durability is limited to a short
period.
Powdered charcoal possesses the elements of efficiency as a
non-conductor in an eminent degree; but its susceptibility of taking
fire militates strongly against its adoption as a boiler covering.
Besides the materials above mentioned, there are some which come under
the denomination of cements; but the use of such is somewhat at variance
with what a dull world would call "facts." Employing them as a clothing
for a vessel in which it is necessary to retain heat is certainly the
wrong way of doing a light thing, if the evidence of distinguished
experimenters be worth anything.
The researches of most well-informed physical philosophers go to prove
that the conducting properties of bodies are augmented by cohesion, and
that heat is conveyed profusely and energetically through all solid and
ponderable substances. Thus gold, silver, and others of the most solid
metals are the best conductors. Next to the pure metals in conducting
powers are rocks, flints, porcelain, earthenware, and the denser liquids
as the solutions of the acids and alkalies. As a further evidence to
prove that the passage of heat through all substances is increased
by cohesion, even some of those which are known to be among the best
conductors are deprived of this property by a division or disintegration
of their particles. Pure silica in the state of hard, rock crystal is
a better conductor than bismuth or lead; but if the rock crystal be
pulverized, the diffusion of heat through its powder is very slow and
feeble. Heat is conducted swiftly and copiously through transparent
rock salt, but pulverization converts the solid mass into a good
non-conductor. Caloric has for the same reason a stronger affinity for
pure metals than for their oxides.
Again, wood is known to be a better non-conductor when reduced to
shavings or sawdust than when in the solid state. It is probably on this
account that trees are protected by bark, which is not nearly so dense
and hard a body as the wood. Wool, silk, and cotton are much diminished
in conducting qualities when spun and woven, for the reason that their
fibers are brought closer together.
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