Various - Scientific American Supplement, No. 312, December 24, 1881

V >> Various >> Scientific American Supplement, No. 312, December 24, 1881

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ELECTRIC TRANSMISSION OF POWER.

In addition to the modes of transmission I have already mentioned,
there is the transmission of power by means of gas. I think that there
is a very large future indeed for gas engines. I do not know whether
this may be the place to state it, but I believe the way in which we
shall utilize our fuel hereafter will, in all probability, not be by
the way of the steam-engine. Sir William Armstrong alluded to this
probability in his address, and I entirely agree, if he will allow me
to say so, that such a change in the production of power from fuel
appears to be impending, if not in the immediate future, at all events
in a time not very far remote; and however much the Mechanical Section
of the British Association may to-day contemplate with regret, even
the mere distant prospect of the steam-engine being a thing of the
past, I very much doubt whether those who meet here fifty years hence
will then speak of it as anything more than a curiosity to be found in
a museum. With respect to the transmission of power electrically, I
won't venture to touch upon that; but will content myself by reminding
you that while Sir William Armstrong did say that there were
comparatively small streams which could be utilized, he did not inform
you of that which he himself had done in this direction; let me say
that Sir William Armstrong thus utilized a fall of water, situated
about a mile from his house, to work a turbine, which drives a dynamo
machine, generating electricity, for the illumination of the house.
When I was last at Crag Side, that illumination was being effected by
the arc light, but since then, as Sir William Armstrong has been good
enough to write to me, he has replaced the arc light by the
incandescent lamp (a form of electrical lighting far more applicable
than the arc light to domestic purposes), and with the greatest
possible success. Thus, in Sir William Armstrong's own case, a small
stream is made to afford light in a dwelling a mile away. Certainly
nothing could have seemed more improbable fifty years ago than that
the light of a house should be derived from a fall of water without
the employment of any kind or description of fuel.

The next subject upon which I propose to touch is that of

THE MANUFACTURE OF IRON AND STEEL.

In 1831, Neilson's hot blast specification had been published for two
and a half years only. The Butterly Company had tried the hot blast
for the first time in the November preceding the meeting of the
British Association. The heating of the blast was coming very slowly
into use, and the temperature attained when it was employed was only
some 600 degrees. The ordinary blast furnace of those days was 35 to
40 feet high, and about 12 feet diameter at the boshes, and turned out
about 60 tons a week. It used about 21/2 tons of coal per ton of iron,
and no attempt was made to utilize the waste gases, whether escaping
in the form of gas or in the form of flame, the country being
illuminated for miles around at night by these fires. The furnaces
were also open at the hearth, and continuous fire poured out along
with the slag.

In 1881, blast furnaces are from 90 ft. to 100 ft. high, and 25 ft. in
diameter at the boshes; they turn out from 500 to 800 tons a week. The
tops and also the hearths are closed, and the blast--thanks to the use
of Mr. E.A. Cowper's stoves--is at 1,200 degrees. The manufacture of
iron has also now enlisted in its service the chemist as well as the
engineer, and among those who have done much for the improvement of
the blast furnaces, to no one is greater praise due than to Mr. Isaac
Lowthian Bell, who has brought the manufacture of iron to the position
of a highly scientific operation. In the production of wrought iron by
the puddling process, and in the subsequent mill operations, there is
no very considerable change, except in the magnitude of the machines
employed, and, in the greater rapidity with which they now run. In
saying this, I am not forgetting the various "mechanical puddlers"
which have been put to work, nor the attempts that have been made by
the use of some of them to make wrought iron direct from the ore; but
neither the "mechanical puddler" nor the "direct process" has yet come
into general use; and I desire to be taken as speaking of that which
is the ordinary process pursued at the present in puddled iron
manufactures. In 1831, a few hundredweights was the limit of weight of
a plate, while in 1881, there may readily be obtained, for
boiler-making purposes, plates of at least four times the weight of
those that were made in 1831. I may, perhaps, be allowed to say that
there is an extremely interesting blue-book of the year 1818,
containing the report of a parliamentary committee which sat on boiler
explosions, and I recommend any mechanical engineer who is interested
in the history of the subject to read that book; he will find it there
stated that in the North of England there was a species of engines
called locomotives, the boilers of which were made of wrought iron,
beaten, not rolled, because the rolled plate was not considered fit;
it was added that if made of beaten iron the boiler would last at
least a year.

In 1831, thirteen years later, the dimensions of rolled plates were no
doubt raised; but few then would have supposed it possible there
should be rolled such plates as are now produced for boiler purposes,
and still fewer would have believed that in the year 1881 we should
make, for warlike purposes, rolled plates 22 inches in thickness and
30 tons in weight. I have said there is very little alteration in the
process of making wrought iron by puddling, and I do not think there
is likely to be much further, if any, improvement in this process,
because I believe that, with certain exceptions, the manufacture of
iron by puddling is a doomed industry. I ventured to say, in a lecture
I delivered at the Royal Institution three years ago on "The Future of
Steel," that I believed puddled iron, except for the mere hand wrought
forge purposes of the country blacksmith, and for such like purposes,
would soon become a thing of the past. Mr. Harrison, the engineer of
the North-Eastern Railway, told me that about eighteen months ago the
North-Eastern Railway applied for tenders for rails in any quantities
between 2,000 and 10,000 tons, and they issued alternative
specifications for iron and for steel. They received about ten
tenders. Some did not care to tender for iron at all; but when they
did tender alternatively, the price quoted for the iron was greater
than for the steel. I have no doubt whatever that, in a short time, it
will be practically impossible to procure iron made by the puddling
process, of dimensions fit for many of the purposes for which a few
years ago it alone was used.

With respect to steel, in 1831 the process in use was that of
cementation, producing blistered steel, which was either piled and
welded to make shear steel, or was broken into small pieces, melted in
pots, and run into an ingot weighing only some 50 lb. or 60 lb. At
that time steel was dealt in by the pound; nobody thought of steel in
tons. In 1881, we are all aware that, by Sir Henry Bessemer's
well-known discovery, carried out by him with such persistent vigor,
cast iron is, by the blowing process, converted into steel, and that
of Dr. Siemens' equally well-known process (now that, owing to his
invention of the regenerative furnace, it is possible to obtain the
necessary high temperature), steel is made upon the open hearth. We
are, moreover, aware that, by both of these processes, steel is
produced in quantities of many tons at a single operation, with the
result that as instanced in the case of the North-Eastern rails, steel
is a cheaper material than the wrought iron made by the puddling
process. One cannot pass away from the steel manufacture without
alluding to Sir Joseph Whitworth's process of putting a pressure on
the steel while in a tried state. By this means, the cavities which
are frequently to be found in the ingot of a large size are, while the
steel is fluid, rendered considerably smaller, and the steel is
thereby rendered much more sound. In conclusion of my observations on
the subject of iron and steel manufacture, I wish to call attention to
the invention of Messrs. Thomas & Gilchrist, by which ores of iron,
containing impurities that unfitted them to be used in the manufacture
of steel, are now freed from these impurities, and are thus brought
into use for steel-making purposes.

BRIDGES.

In the year 1831, bridges of cast iron existed; but no attempt had
been made to employ wrought iron in girder bridges, although Telford
had employed it in the Menai Suspension Bridge; but in 1881, the
introduction of railways, and the improvement in iron manufactures,
have demanded, and have rendered possible the execution of such
bridges as the tubular one, spanning the Menai Straits, in span of 400
feet, and the Saltash, over the Tamar, with spans of 435 feet; while
recent great improvements in the manufacture of steel have rendered
possible the contemplated construction of the Forth Bridge, where
there are to be spans of 1,700 feet, or one-third of a mile in length.
Mr. Barlow, one of the engineers of this bridge, has told me that
there will be used upwards of 2,000 more tons of material in the Forth
Bridge, to resist the wind pressure, than would have been needed if no
wind had to be taken into account, and if the question of the simple
weight to be carried had alone to be considered. With respect to the
foundation of bridges, that ingenious man, Lord Cochrane, patented a
mode of sinking foundations, even before the first meeting of the
British Association, viz., as far back, I believe, as 1825 or 1826;
and the improvements which he then invented are almost universally in
use in bridge construction at the present day. Cylinders sunk by the
aid of compressed air, airlocks to obtain access to the cylinder, and,
in fact, every means that I know of as having been used in the modern
sinking of cylinder foundations, were described by Lord Cochrane
(afterwards Earl of Dundonald) in that specification.

The next subject I propose to touch on is that of

MACHINE TOOLS.

In 1831, the mention of lathes, drilling machines, and screwing
machines brings me very nearly to the end of the list of the machine
tools used by turners and fitters, and at that time many lathes were
without slide rests. The boiler-maker had then his punching-press and
shearing machine; the smith, leaving on one side his forges and their
bellows, had nothing but hand tools, and the limit of these was a huge
hammer, with two handles, requiring two men to work it. In anchor
manufacture, it is true, a mechanical drop-hammer, known as a
Hercules, was employed, while in iron works, the Helve and the Tilt
hammer were in use. For ordinary smith's work, however, there were, as
has been said, practically no machine tools at all.

This paucity or absence in some trades, as we have seen, of machine
tools, involved the need of very considerable skill on the part of the
workman. It required the smith to be a man not only of great muscular
power, but to be possessed of an accurate eye and a correct judgment,
in order to produce the forgings which were demanded of him, and to
make the sound work that was needed, especially when that soundness
was required in shafts, and in other pieces which, in those days, were
looked upon as of magnitude; which, indeed, they were, relatively to
the tools which could be brought to operate upon them. The
boiler-maker in his work had to trust almost entirely to the eye for
correctness of form and for regularity of punching, while all parts of
engines and machines which could not be dealt with in the lathe, in
the drilling, or in the screwing machine, had to be prepared by the
use of the chisel and the file.

At the present day, the turning and fitting shops are furnished not
only with the slide lathe, self acting in both directions, and
screw-cutting, the drilling-machine, and the screwing machine, but
with planing machines competent to plane horizontally, vertically, or
at an angle; shaping machines, rapidly reciprocating, and dealing with
almost any form of work; nut shaping machines, slot drilling
machines, and slotting machines, while the drills have become multiple
and radial; and the accuracy of the work is insured by testing on
large surface plates, and by the employment of Whitworth internal and
external standard gauges.

The boiler maker's tools now comprise the steam, compressed air,
hydraulic or other mechanical riveter, rolls for the bending of plates
while cold into the needed cylindrical or conical forms, multiple
drills for the drilling of rivet holes, planing machines to plane the
edges of the plates, ingenious apparatus for flanging them, thereby
dispensing with one row of rivets out of two, and roller expanders for
expanding the tubes in locomotive and in marine boilers; while the
punching press, where still used, is improved so as to make the holes
for seams of rivets in a perfect line, and with absolute accuracy of
pitch.

With respect to the smith's shop, all large pieces of work are now
manipulated under heavy Nasmyth or other steam hammers; while smaller
pieces of work are commonly prepared either in forging machines or
under rapidly moving hammers, and when needed in sufficient numbers
are made in dies. And applicable to all the three industries of the
fitting shop, the boiler shop, and the smith's shop, and also to that
other industry carried on in the foundry, are the traveling and swing
cranes, commonly worked by shafting, or by quick moving ropes for the
travelers, and by hydraulic power or by steam engines for the swing
cranes. It may safely be said, that without the aid of these
implements, it would be impossible to handle the weights that are met
with in machinery of the present day.

I now come to one class of machine which, humble and small as it is,
has probably had a greater effect upon industry and upon domestic life
than almost any other. I mean

THE SEWING MACHINE.

In 1831, there was no means of making a seam except by the laborious
process of the hand needle. In 1846, Eldred Walker patented a machine
for parsing the basting thread through the gores of umbrellas, a
machine that was very ingenious and very simple, but was utterly
unlike the present sewing machine, with its eye-pointed needle, using
sometimes two threads (the second being put in by a shuttle or by
another needle), and making stitches at twenty-fold the rapidity with
which the most expert needlewoman could work. By means of the sewing
machine not only are all textile fabrics operated upon, but even the
thickest leather is dealt with, and as a _tour de force_, but as a
matter of fact, sheet-iron plates themselves have been pierced, and
have been united by a seam no boilermaker ever contemplated, the
piercing and the seam being produced by a Blake sewing machine. I
believe all in this section will agree that the use of the sewing
machine has been unattended by loss to those who earn their living by
the needle; in fact, it would not be too much to say that there has
been a positive improvement in their wages.

The next matter I have to touch upon is

AGRICULTURAL MACHINERY.

In 1831, we had thrashing machines and double plows, and even multiple
plows had been proposed, tried, and abandoned. Reaping machines had
been experimented with and abandoned; sowing machines were in use, but
not many of them; clod crushers and horse rakes were also in use; but
as a fact plowing was done by horse power with a single furrow at a
time, mowing and reaping were done by the scythe or the sickle,
sheaves were bound by hand, hay was tedded by hand-rakes, while all
materials and produce were moved about in carts and in wagons drawn by
horses. At the present time we have multiple plows, making five or six
furrows at a time, these and cultivators also, driven by steam,
commonly from two engines on the head lands, the plow being in
between, and worked by a rope from each engine, or if by one engine, a
capstan on the other head land, with a return rope working the plow
backward and forward; or by what is known as the roundabout system,
where the engine is fixed and the rope carried round about the field;
or else plows and cultivators are worked by ropes from two capstans
placed on the two head lands, and driven by means of a quick-going
rope, actuated by an engine, the position of which is not changed. And
then we have reaping machines, driven at present by horses; but how
long it will be before the energy residing in a battery, or that in a
reservoir of compressed air, will supersede horse power to drive the
reaping machine, I don't know, but I don't suppose it will be very
long. The mowing and reaping machines not only cut the crop and
distribute it in swaths, or, in the case of the reaping machine, in
bundles, but now, in the instance of these latter machines, are
competent to bind it into sheaves. In lieu of hand tedding, haymaking
machines are employed, tossing the grass into the air, so as to
thoroughly aerate it, taking advantage of every brief interval of fine
weather; and seed and manure are distributed by machine with unfailing
accuracy. The soil is drained by the aid of properly constructed plows
for preparing the trenches; roots are steamed and sliced as food for
cattle; and the thrashing machine no longer merely beats out the
grain, but it screens it, separates it, and elevates the straw, so as
to mechanically build it up into a stack. I do not know a better class
of machine than the agricultural portable engine. Every part of it is
perfectly proportioned and made; it is usually of the locomotive type,
and the economy of fuel in its use is extremely great. I cannot help
thinking that the improvement in this respect which has taken place in
these engines, and the improvement of agricultural machinery
generally, is very largely due to the Royal Agricultural Society, one
of the most enterprising bodies in England.

I now come to the very last subject I propose to speak upon, and that
is

PRINTING MACHINERY,

and especially as applied to the printing of newspapers. In 1831, we
had the steam press sending out a few hundred copies in an hour, and
doing that upon detached sheets, and thus many hours were required for
an edition of some thousands. The only way of expediting the matter
would have been to have recomposed the paper, involving, however,
double labor to the compositors, and a double chance of error. At the
present day, we have, by the Walter press, the paper printed on a
continuous sheet at a rate per hour at least three times as great as
that of the presses of 1831, and, by the aid of _papier mache_ moulds,
within five minutes from the starting of the first press, a second
press can be got to work from the stereotype plates, and a third one
in the next five minutes; and thus the wisdom of our senators, which
has been delivered as late as three o'clock in the morning, is able to
be transmitted by the newspaper train leaving Euston at 5:15 A.M.

This is the last matter with which I shall trouble the Section. I have
purposely omitted telegraphy; I have purposely omitted artillery,
textile fabrics, and the milling and preparation of grain. These and
other matters I have omitted for several reasons. Some I have omitted
because I was incompetent to speak upon them, others because of the
want of time, and others because they more properly belong to Section
A.

I hope, sir, although your address, dealing with the future, was
undoubtedly the right address for a president to deliver, and although
it is equally right that we should not content ourselves with merely
looking back in a "rest and be thankful" spirit at the various
progress which this paper records, it may nevertheless be thought well
that there should have been brought before the section, in however
cursory a manner, some notice of mechanical development during the
past fifty years.

* * * * *

[Continued from SUPPLEMENT, No. 311, page 4954.]

AMATEUR MECHANICS.

METAL TURNING.

In selecting a lathe an amateur may exercise more or less taste, and
he may be governed somewhat by the length of his purse; the same is
true in the matter of chucks; but when he comes to the selection or
making of turning tools he must conform to fundamental principles; he
must profit as far as possible by the experience of others, and will,
after all, find enough to be learned by practice.

Tools of almost every description may be purchased at reasonable
prices, but the practice of making one's own tools cannot be too
strongly recommended. It affords a way out of many an emergency, and
where time is not too valuable, a saving will be realized. A few bars
of fine tool steel, a hammer, and a small anvil, are all that are
required, aside from fire and water. The steel should be heated to a
low red, and shaped with as little hammering as possible; it may then
be allowed to cool slowly, when it may be filed or ground to give it
the required form. It may now be hardened by heating it to a cherry
red and plunging it straight down into clean cool (not too cold)
water. It should then be polished on two of its sides, when the temper
may be drawn in the flame of an alcohol lamp or Bunsen gas burner; or,
if these are not convenient, a heated bar of iron may be used instead,
the tool being placed in contact with it until the required color
appears. This for tools to be used in turning steel, iron, and brass
may be a straw color. For turning wood it may be softer. The main
point to be observed in tempering a tool is to have it as hard as
possible without danger of its being broken while in use. By a little
experiment the amateur will be able to suit the temper of his tools to
the work in hand.

In the engraving accompanying the present article a number of hand
turning tools are shown, also a few tools for the slide rest. These
tools are familiar to machinists and may be well known to many
amateurs; but we give them for the benefit of those who are
unacquainted with them and for the sake of completeness in this series
of articles.

[Illustration: TURNING TOOLS.]

Fig. 1 is the ordinary diamond tool, made from a square bar of steel
ground diagonally so as to give it two similar cutting edges. This
tool is perhaps more generally useful than any of the others. The
manner of using it is shown in Fig. 23; it is placed on the tool rest
and dexterously moved on the rest as a pivot, causing the point to
travel in a circular path along the metal in the lathe. Of course only
a small distance is traveled over before the tool is moved along on
the rest. After a little experience it will be found that by
exercising care a good job in plain turning may be done with the tool.

Fig. 2 shows a sharp V shaped tool which will be found useful for many
purposes. Fig. 3 is a V shaped tool for finishing screw threads. Figs.
4 and 5 are round-nosed tools for concave surfaces; Fig. 6, a square
tool for turning convex and plane surfaces. The tool shown in Fig. 7
should be made right and left; it is useful in turning brass, ivory,
hard wood, etc. Fig. 8 is a separating tool; Fig. 9 is an inside tool,
which should be made both right and left, and its point may be either
round, V shaped, or square. Fig. 24 shows the manner of holding an
inside tool. Fig. 10 is a tool for making curved undercuts. Fig. 11 is
a representative of a large class of tools for duplicating a given
form.

These figures represent a series of tools which may be varied
infinitely to adapt them to different purposes. The user, if he is
wide awake, is not long in discovering what angle to give the cutting
edge, what shape to give the point, and what position to give the tool
in relation to the work to be done.

Having had experience with hand tools it requires only a little
practice and observation to apply the same principles to slide rest
tools.

A few examples of this class of tools are given. Fig. 12 is the
ordinary diamond pointed tool, which should be made right and left.
The cutting edge may have a more or less acute angle, according to the
work to be done, and the inclined or front end of the tool may be
slightly squared or rounded, according to the work. Fig. 13 is a
separating tool, which is a little wider at the cutting edge than any
where else, so that it will clear itself as it is forced into the
work.

For brass this tool should be beveled downward slightly. By giving the
point the form shown in Fig. 3 it will be adapted to screw cutting.

Fig. 14 shows an inside tool for the slide rest; its point may be
modified according to the work to be done. Fig. 15 is a side tool for
squaring the ends of shafts; Figs. 16, 17, 18, and 19 represent tools
for brass, Fig. 16 is a round-nosed tool for brass, Fig. 17 a V shaped
tool, Fig. 18 a screw thread tool, and Fig. 19 a side tool. In boring,
whether the object is cored or not, it is desirable, where the hole is
not too large, to take out the first cut with a drill. The drill for
the purpose is shown in Fig. 20, the drill holder in Fig. 21, and the
manner of using in Fig 22. The drill holder, B, is held by a mortised
post placed in the rest support. The slot of the drill holder is
placed exactly opposite the tail center and made secure. The drill,
which is flat, is drilled to receive the tail center, and it is kept
from turning by the holder, and is kept from lateral movement and
chattering by a wrench, C, which is turned so as to bind the drill in
the slot of the holder.

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