Various - Scientific American Supplement, No. 312, December 24, 1881
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Various >> Scientific American Supplement, No. 312, December 24, 1881
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9 [Illustration]
SCIENTIFIC AMERICAN SUPPLEMENT NO. 312
NEW YORK, DECEMBER 24, 1881.
Scientific American Supplement. Vol. XII., No. 312.
Scientific American established 1845
Scientific American Supplement, $5 a year.
Scientific American and Supplement, $7 a year.
* * * * *
TABLE OF CONTENTS.
I. ENGINEERING AND MECHANICS.--Improved Fifteen Ton Traveling
Crane. Designed for service in the construction of Port
Alfred Harbor. South Africa. 3 figures. 4967
Improved Steam Boiler. 1 figure. 4968
The Elevated Railways of New York. 4968
Some of the Developments of Mechanical Engineering during the
Last Half Century. British Association Paper. By SIR FREDERICK
BRAMWELL. The steam engine.--Evaporative condenser.--Steam
navigation.--Marine governors.--Light engines and boilers.--The
Perkins system.--Ether engine.--Quicksilver engine.--Locomotive
engines.--Brakes.--Motors.--Transmission of power.--Compressed
air locomotives.--Hydraulic transmission of power.--Electric
transmission of power.--The manufacture of iron and steel.--
Bridges.--Machine tools.--The sewing machine.--Agricultural
machinery.--Printing machinery. 4968
Amateur Mechanics: Metal turning, 29 figures. Rotary cutters,
12 figures. Wood-working and lathe attachments, 9 figures. 4971
A New Method of Keeping Mechanical Drawings. 4978
Achard's Electric Brake for Railway Use. 2 figures. Plan and
elevation. 4974
II. ELECTRICITY, ETC.--Electricity. What it is and what may be
expected of it. By JACOB REESE. 4974
Electric Light Apparatus for Photographic Purposes. By A.J.
JARMAN. 2 figures. 4976
Desruelles's Electric Lighter. 1 figure. 4976
Solenoid Underground Wires in Philadelphia. 4976
Dr. Herz's Telephonic Systems. 2 figures. 4976
Decision of the Congress of Electricians on the Units of
Electric Measures. 4977
Secondary Batteries. By J. ROUSSE. 4977
III. TECHNOLOGY AND CHEMISTRY.--Domestic Sugar Production. 4980
M. Garnier's New Methods of Photo-Engraving. By Major J.
WATERHOUSE.--Photogravure.--Photograph printing by
vapor.--Atmography. 4982
Dangers of Pyrogallic Acid. By DR. T.L. PHIPSON. 4982
IV. ARCHITECTURE, ETC.--Artists' Homes, No. 12.--Wm. Emerson's
house, Little Sutton, Chiswick.--Full page illustration and
large size longitudinal section. 4978
Memorable English Houses. 4 figures.--Newton's house.--
Flaxman's house.--Canning's house.--Johnson's house. 4980
V. GEOGRAPHY.--Herald Island.--On the summit.--A midnight
observation.--Plant life on Herald Island.--Inhabitants of
the cliffs. 4980
VI. METALLURGY.--The Treatment of Quicksilver Ores in Spain. 4977
VII. AERONAUTICS.--The Balloon in Aeronautics. 4977
VIII. BIOGRAPHY.--Franz Liszt.--Large Portrait. 4981
* * * * *
IMPROVED FIFTEEN TON CRANE.
[Illustration: Engraving.]
[Illustration: Side and Top View Plans.
IMPROVED FIFTEEN TON TRAVELING CRANE.]
The machine illustrated on first page has been constructed for Port
Alfred Harbor, this being one of several harbors now being made by Sir
J. Coode in South Africa. The pier for the construction of which the
crane will be employed will consist of concrete blocks laid on what is
known as the "overend system." The blocks, being brought on trucks
direct from the block yard to within the sweep of the machine, are
raised by it, swung round, and accurately set, the machine being
continually traveled forward as the work advances. The bottom blocks
are laid on bags of concrete previously deposited by the crane out of
boxes with flap bottoms.
The present machine has been specially designed throughout, and
represents the most complete development which block-setting plant has
yet attained.
The most striking features of the crane are, the great range of all
the motions, the large radius, and the method of providing for the
latter by a horizontal jib suspended from a king-post. It was at first
intended to have a straight inclined jib, and to alter the radius by
pivoting this round its lower end, as is commonly done; it occurred,
however, to Mr. Matthews, M.I.C.E., representing Sir J. Coode, that
the plan eventually adopted would be in many ways preferable; the
crane was therefore constructed by Messrs. Stothert & Pitt with this
modification, and as far as can be judged from the trial with proof
load, the arrangements can hardly be surpassed for quick and accurate
block-setting. In cranes with "derricking" jibs it is necessary to
connect the derrick and hoisting gears in such a manner that a
variation of the radius may not affect the level of the load; this
plan answers sufficiently well for ordinary purposes, but for
block-setting it is requisite to have extreme accuracy in all the
movements and great quickness in changing from one to another; the
arrangements adopted in foundry cranes, in which all the motions are
entirely independent of one another, seems therefore more suited for
this kind of work. Other not inconsiderable advantages are also
secured by the adoption of the foundry crane type, the amount of clear
headway under the jib being much increased, and the difficulty avoided
of making a jib sixty feet long sufficiently stiff without undue
weight.
The principal dimensions of the crane are, total height of lift 46
feet, radius variable from 25 feet minimum to 45 feet maximum, height
from rail to underside of jib 22 feet 23/4 inches, radius of tail to
center of boiler 22 feet, working load 15 tons, proof load 19 tons.
The general arrangement consists of a truck on which is fixed a post,
round which the crane revolves; the jib is supported midway by an
inclined strut, above which is placed the king-post; the strut is
curved round at the bottom and forms one piece with the side frames,
which are carried right back as a tail to support the boiler and
balance weight.
The hoisting gear consists of a double system of chains 13/16 in. in
diameter placed side by side; each chain is anchored by an adjustable
screw to the end of the jib, and, passing round the traveling carriage
and down to the falling block, is taken along the jib over a sliding
pulley which leads it on to the grooved barrel, 3 ft. 9 in. in
diameter. In front of the barrel is placed an automatic winder which
insures a proper coiling of the chain in the grooves. The motive power
is derived from two cylinders 10 in. in diameter and 16 in. stroke,
one being bolted to each side frame; these cylinders, which are
provided with link motion and reversing gear, drive a steel crank
shaft 23/4 in. in diameter; on this shaft is a steel sliding pinion
which drives the barrel by a double purchase.
In the center of the crank-shaft is a large reversing friction clutch,
which drives, through miter gear, a vertical shaft placed just in
front of the post; from the latter the slewing, racking, and traveling
motions are obtained.
The crane can be turned through a complete circle by a pinion gearing
into a machine-moulded toothed ring bolted to the top of the truck;
this ring is 11 ft. 4-7/8 in. in diameter, and contains 172 teeth 21/2
in pitch. The slewing pinion is driven by intermediate gearing from
the bottom of the vertical shaft mentioned above. For the turning
motion two distinct sets of rollers are provided; these are carried by
cross-girders placed between the side frames; one set runs against a
cast-iron roller path bolted round the bottom of the post, and the
other on the large horizontal roller path seen in the engraving. The
latter is 14 ft. in diameter; it is built up of two deep curved
channel irons with top and bottom plates forming a circular box
girder, on the top of which a heavy flat rail is riveted, and the
whole turned up in the lathe. The racking and traveling motions are
driven from the top end of the vertical shaft; the racking gear
consists of wire ropes attached to each side of the traveling carriage
and coiled round a large barrel, the outer rope being brought over a
pulley at the end of the jib. The rails for the carriage rest on
rolled joints bolted to the underside of jib. This arrangement
involves the use of an overhung traveling carriage, but enables the
jib to be of a stiff box section, the side stiffness being further
secured by wind ties.
The traveling motion is worked by a second vertical shaft, which
passes down the center of the post, and by means of a cross shaft is
geared to the front axle, from which four of the ground wheels are
driven.
The post is octagonal, built up of plates 3/4 in. thick; at the bottom
end it is secured to the girders of the truck, and at the top is
shrunk on to a large gudgeon 12 in. in diameter, which enters a
casting fixed in the back end of the jib; on the top of the gudgeon
are two steel disks on which an adjustable cap rests; by means of this
and the ties to the tail and the lower end of the strut a proportion
of the weight can be brought on to the post so as to relieve the
roller path to any desired extent, and enable the crane to be revolved
easily.
The truck is 24 ft. long and 16 ft. 41/2 in. wide; it is constructed of
longitudinal and transverse box girders 2 ft. 8 in. deep, and rests on
two axles 6 in. in diameter; round these axles swivel the cast-iron
bogie frames which carry the ground wheels. This arrangement was
adopted because the crane has to travel up a gradient of 1 in 30, and
the bogies enable it to take the incline better; they also distribute
the weight more evenly on the wheels. The gauge of the rails is 15 ft,
the wheels are 2 ft. 6 in. in diameter, and have heavy steel tires.
The weight on each of the front wheels when running with the ballast,
but no load, is about 16 tons. A powerful brake is applied to the
wheels when descending the incline.
All the clutch levers, break treadle, and handles are brought
together, so that one man has the crane under his entire control. An
iron house, of which the framing only is shown, extends from the
gearing right back to the boiler, forming a most spacious engine room
and stokehole. A separate donkey engine is provided for feeding the
boiler. The truck is furnished with legs under which packings can be
wedged so as to relieve the load on the wheels when block-setting. The
slings seen under the boiler are for hanging a concrete balance
weight; this will weigh about 20 tons. The weight of the crane itself
without load or ballast is about 80 tons. The crane was tested under
steam with a load of 19 tons with the most satisfactory results; the
whole machine appeared to be very rigid, an end often very difficult
to obtain with portable wrought-iron structures and live loads. The
result in the present case is probably greatly due to the careful
workmanship, and to the fact that the sides and ends of the plates are
planed throughout, so that the webs of the girders get a fair bearing
on the top and bottom plates.
The crane showed itself to be very handy and quick in working, the
speeds with 19 tons load, as actually timed at the trial, are: lifting
16 ft. per minute, racking motion 46 ft. per minute, slewing through a
complete circle 90 ft. diameter, four minutes, equivalent to a speed
at load of 60 ft. per minute. The crane was constructed by Messrs.
Stothert & Pitt, of Bath, to the order of the Crown agents for the
colonies, and we understand that the design and construction have
given complete satisfaction to Sir J. Coode, the engineer to the
harbor works, under whose supervision the crane was
constructed.--_Engineering._
* * * * *
IMPROVED STEAM-BOILER.
An improvement in steam-boilers, best understood by reference to the
ordinary vertical form, has been introduced by Mr. T. Moy, London.
Here the flue is central, and, as shown in the accompanying
illustration, is crossed by a number of horizontal water-tubes at
different heights. The ends of these tubes are embraced, within the
steam chamber, by annular troughs. At the top domed part of the boiler
are two annular chambers, the outer one being intended to receive the
water upon entry from the feed-pump, and to contain any sedimentary
deposit which may be formed. The water next passes, by the pipe, _a_,
in the figure, into the inner chamber, surrounding the end of the
uptake flue, whence it flows through the pipe, _b_, down into the
first of the annular troughs above mentioned, and afterward overflows
these troughs in succession until it reaches the bottom. Mr. Moy
claims to have secured by this means a boiler of quick steaming
capacity, together with a reduction in the weight of metal, and
considerable economy of fuel. By the arrangement of the water in a
number of shallow layers a large steaming surface is obtained, and
there is a good steam space rendered available round the troughs. The
water also enters at a point where it may abstract as much heat as
possible from the furnace gases before they escape; and by the
separation of the top domed chamber from the rest of the boiler the
operation of scaling and cleaning is facilitated. The arrangement is
also adapted to horizontal and multitubular boilers, to be fired with
solid, liquid, or gaseous fuel.
[Illustration: IMPROVED BOILER.]
* * * * *
THE ELEVATED RAILWAYS OF NEW YORK.
But few persons who have not been in New York since the construction
of the elevated roads, and witnessed their equipments and operations,
can have any adequate idea of the extent of them, and of the people,
machinery, and appurtenances required in working them. A recent
inventory discloses the fact that there are 32 miles of roadway, 161
stations, 203 engines, and 612 cars, while 3,480 trains a day are run.
There are 3,274 men employed on these roads, 309 of whom are
engineers, 258 ticket agents, 231 conductors, 308 firemen, 395 guards
or brakemen, 347 gatemen, 4 road inspectors, 106 porters, 33
carpenters, 27 painters, 69 car inspectors, 140 car cleaners, 40 lamp
men, and 470 blacksmiths, boiler makers, and other mechanics employed
on the structure and in the shops. Most of the ticket agents are
telegraph operators, but there are 13 other operators employed. There
are four double-track lines in operation. The aggregate daily receipts
vary from $14,000 to $18,000; and as many as 274,023 passengers have
been carried in one day. Engineers are paid from $3 to $3.50 per day;
ticket agents, $1.75 to $2.25; conductors, $1.90 to $2.50; firemen,
$1.90 to $2; guards or brakemen, $1.50 to $1.65; and gatemen, $1.20 to
$1.50. The above items do not include machinists and other _employes_
in the workshops, or the general officers, clerks, etc.
* * * * *
AMERICAN ANTIMONY.
A Baltimore dispatch informs us that a carload of antimony, ten tons
in all, was lately received by C.L. Oudesluys & Co., from the southern
part of Utah Territory, being the first antimony received in the East
from the mines of that section. The antimony was mined about 140 miles
from Salt Lake City. The ore is a sulphide, bluish gray in color, and
yields from 60 to 65 per cent. of antimony. All antimony heretofore
came from Great Britain and the island of Borneo, and paid an import
duty of 10 per cent. ad valorem, and there is also some from Sonora.
It is believed that with proper rail facilities to the mines of the
West there will be no need of importations.
* * * * *
SOME OF THE DEVELOPMENTS OF MECHANICAL ENGINEERING DURING THE
LAST HALF-CENTURY.[1]
[Footnote 1: Paper read in Section G (Mechanical) of the British
Association.]
By SIR FREDERICK BRAMWELL, V.P. Inst. C.E., F.R.S.,
Chairman of the Council of the Society of Arts.
I am quite sure the section will agree with me in thinking it was very
fortunate for us, and for science generally, that our president
refrained from occupying the time of the section by a retrospect, and
devoted himself, in that lucid and clear address with which he favored
us, to the consideration of certain scientific matters connected with
engineering, and to the foreshadowing of the directions in which he
believes it possible that further improvements may be sought for. But
I think it is desirable that some one should give to this section a
record, even although it must be but a brief and an imperfect one, of
certain of the improvements that have been made, and of some of the
progress that has taken place, during the last fifty years, in the
practical application of mechanical science, with which science and
its applications our section is particularly connected. I regret to
say that, like most of the gentlemen who sat on this platform
yesterday, who, I think, were, without exception, past presidents of
the section, I am old enough to give this record from personal
experience. Fifty years ago I had not the honor of being a member, nor
should I, it is true, have been eligible for membership of the
association; but I was at that time vigorously making models of
steam-engines, to the great annoyance of the household in which I
lived, and was looking forward to the day when I should be old enough
to be apprenticed to an engineer. Without further preface, I will
briefly allude to some of the principal developments of a few of the
branches of engineering. I am well aware that many branches will be
left unnoticed; but I trust that the omissions I may make will be
remedied by those present who may speak upon the subject after me.
I will begin by alluding to
THE STEAM-ENGINE EMPLOYED FOR MANUFACTURING PURPOSES.
In 1831, the steam-engine for these purposes was commonly the
condensing beam engine, and was supplied with steam from boilers,
known, from their shape, as wagon boilers; this shape appears to have
been chosen rather for the convenience of the sweeps, who periodically
went through the flues to remove the soot consequent on the imperfect
combustion, than for the purpose of withstanding any internal pressure
of steam. The necessary consequence was, that the manufacturing
engines of those days were compelled to work with steam of from only
31/2 lb. to 5 lb. per square inch of pressure above atmosphere. The
piston speed rarely exceeded 250 feet per minute, and as a result of
the feeble pressure, and of the low rate of speed, very large
cylinders indeed were needed relatively to the power obtained. The
consumption of fuel was heavy, being commonly from 7 lb. to 10 lb. per
gross indicated horsepower per hour. The governing of the engine was
done by pendulum governors, revolving slowly, and not calculated to
exert any greater effort than that of raising the balls at the end of
the pendulum arms, thus being, as will be readily seen, very
inefficient regulators. The connection of the parts of the engine
between themselves was derived from the foundation upon which the
engine was supported. Incident to the low piston speed was slowness of
revolution, rendering necessary heavy fly wheels, to obtain even an
approach to practical uniformity of rotation, and frequently rendering
necessary also heavy trains of toothed gearing, to bring up the speed
from that of the revolutions of the engine to that of the machinery it
was intended to drive.
In 1881, the boilers are almost invariably cylindrical, and are very
commonly internally fired, either by one flue or by two; we owe it to
the late Sir William Fairbairn, President of the British Association
in 1861, that the danger, which at one time existed, of the collapse
of these fire flues, has been entirely removed by his application of
circumferential bands. Nowadays there are, as we know, modifications
of Sir William Fairbairn's bands, but by means of his bands, or by
modifications thereof, all internally flued boilers are so
strengthened that the risk of a collapse of the flue is at an end.
Boilers of this kind are well calculated to furnish--and commonly do
furnish--steam of from 40 lb. to 80 lb. pressure above atmosphere.
The piston speed is now very generally 400 feet or more, so that,
notwithstanding that there is usually a liberal expansion, the mean
pressure upon the piston is increased, and this, coupled with its
increased speed, enables much more power to be obtained from a given
size of cylinder than was formerly obtainable. The revolutions of the
engine now are as many as from 60 to 200 per minute, and thus, with
far lighter fly-wheels, uniformity of rotation is much more nearly
attained.
THE EVAPORATIVE CONDENSER.
Moreover, all the parts of the engine are self-contained; they no
longer depend upon the foundation, and in many cases the condensing is
effected either by surface condensers, or, where there is not
sufficient water, the condensation is, in a few instances, effected by
the evaporative condenser--a condenser which, I am sorry to say, is
not generally known, and is therefore but seldom used, although its
existence has been nearly as long as that of the association.
Notwithstanding the length of time during which the evaporative
condenser has been known to some engineers, it is a common thing to
hear persons say, when you ask them if they are using a condensing
engine, "I can not use it; I have not water enough." A very sufficient
answer indeed, if an injection condenser or an ordinary surface
condenser constituted the sole means by which a vacuous condition
might be obtained; but a very insufficient answer, having regard to
the existence of the evaporative condenser, as by its means, whenever
there is water enough for the feed of a non condensing engine, there
is enough to condense, and to produce a good vacuum.
The evaporative condenser simply consists of a series of pipes, in
which is the steam to be condensed, and over which the water is
allowed to fall in a continuous rain. By this arrangement there is
evaporated from the outside of the condenser a weight of water which
goes away in a cloud of vapor, and is nearly equal to that which is
condensed, and is returned as feed into the boiler. The same water is
pumped up and used outside the condenser, over and over, needing no
more to supply the waste than would be needed as feed water. Although
this condenser has, as I have said, been in use for thirty or forty
years, one still sees engines working without condensation at all, or
with waterworks water, purchased at a great cost, and to the detriment
of other consumers who want it for ordinary domestic purposes; or one
sees large condensing ponds made, in which the injection water is
stored to be used over and over again, and frequently (especially
toward the end of the week) in so tepid a state as to be unfit for its
purpose. The governing is now done by means of quick-running
governors, which have power enough in them to raise not merely the
weight of the pendulum ball, which is now small, but a very heavy
weight, and in this way the governing is extremely effective. I
propose to say no more, looking at the magnitude of the whole of my
subject, upon the engine used for manufacturing purposes, but rather
to turn at once to those employed for other objects.
STEAM NAVIGATION.
In 1831, there were a considerable number of paddle steamers running
along some of the rivers in England, and across the Channel to the
Continent. But there were no ocean steamers, properly so-called, and
there were no steamers used for warlike purposes. As in the case of
the wagon boilers, the boilers of the paddle steamers of 1831 were
most unsuited for resisting pressure. They were mere tanks, and there
was as much pressure when there was no steam in the boiler from the
weight of the water on the bottom, as there was at the top of the
boiler from the steam pressure when the steam was up. Under these
circumstances, again, from 31/2 lb. to 5 lb. was all the pressure the
boilers were competent to bear, and as the engines ran at a slow
speed, they developed but a small amount of horse-power in relation to
their size. Moreover, as in the land engine, the connection between
the parts of the marine engine was such as to be incompetent to stand
the strain that would come upon it if a higher pressure, with a
considerable expansion, were used, and thus the consumption of coal
was very heavy; and we know that, having regard to the then
consumption, it was said, on high authority, it would be impossible
for a steamboat to traverse the Atlantic, as it could not carry fuel
enough to take it across; and indeed it was not until 1838 that the
Sirius and the Great Western did make the passage. The passage had
been made before, but it was not until 1838 that the passenger service
can be said to have commenced. In 1831, the marine boiler was supplied
with salt water, the hulls were invariably of wood, and the speed was
probably from eight to nine knots an hour. In 1881, the vessels are as
invariably either of iron or of steel, and I believe it will not be
very long before the iron disappears, giving place entirely to the
last mentioned metal. With respect to the term "steel," I am ready to
agree that it is impossible to say where, chemically speaking, iron
ends and steel begins. But (leaving out malleable cast iron) I apply
this term "steel" to any malleable ductile metal of which iron forms
the principal element and which has been in fusion, and I do so in
contradistinction to the metal which may be similar chemically, but
which has been prepared by the puddling process. Applying the term
steel in that sense, I believe, as I have said, it will not be very
long before plate-iron produced by the puddling process will cease to
be used for the purpose of building vessels. With respect to marine
engines, they are now supplied with steam from multiple tubed boilers,
the shells of which are commonly cylindrical. They are of enormous
strength, and made with every possible care, and carry from 80 lb. to
100 lb. pressure on the square inch.
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