AUTOMATICITY AND INITIATION
Self-acting devices abridge labor . . . Trigger effects in the
laboratory, the studio, and the workshop . . . Automatic telephones
. . . Equilibrium of the atmosphere may be easily upset.
At this place we may for a little while consider a few fundamental
principles of construction whereby inventors have economized material,
labor and energy by making their devices self-acting, and by so poising
a contrivance that a mere touch at the right time and place sets it
going.
Steam Engines.
Humphrey Potter was a boy whose duty obliged him to open and shut the
valves of a Newcomen steam-engine as it slowly went its rounds. He was a
human sort of boy, who liked play better than his irksome task, so he
found a way to rid himself of the drudgery of constantly moving his
valve-handles to and fro. He tied a rod to the walking beam in such wise
that it opened the valve at the proper moment, and, at another point in
its circuit, when necessary, closed it. Then and only then did the
steam-engine become self-acting. In the best modern types of engine this
automaticity goes far indeed. Not only does the mechanism pump water as
required into both the boiler and the condenser, it shuts off steam
instantly when the engine moves too swiftly, and, when the engine speed
is sluggish the port betwixt boiler and cylinders is opened to the full.
And further: automatic stokers bear coal into the furnace at a rate
which varies with the demand, should the steam pressure fall through an
undue call for power, then an extra quantity of coal is borne upon the
grate-bars. When oil is the fuel automatic stoking is, of course, at its
best, there being neither cinders nor ashes to be removed--a duty, by
the way, which in large central stations requires extensive machinery,
all automatic.
Self-winding Clocks.
The essence of automaticity is that mechanism at a certain,
predetermined point in an operation shall perform a required act. Thus,
to take the common example of a striking clock: at the end of each hour
a detent is pulled so as to release a hammer which hits a gong the
proper number of times. Let us suppose the clock to be driven by a
weight or a spring in the ordinary way; every day or every week the
weight or spring will require to be wound up. In time-pieces of a new
variety the period during which no attention whatever is needed is
lengthened to a year. The Self-winding Clock Company, of Brooklyn, New
York, makes a clock which is driven by a fine spring, much like a common
clock; that spring every hour is automatically wound up by a tiny
electric motor connected with a small battery in the clock case. An
attachment is provided by which, through the wires of the Western Union
Telegraph Company, the clock is every hour regulated to the standard
time of the National Observatory at Washington. The charge for this
service is one dollar a month.
[Illustration: Stop-motion.]
Looms and Presses.
To-day a designer always seeks to make a machine self-acting, to limit
the operator’s task to starting, directing, and stopping, all with the
utmost facility and the least possible exertion. So far has success gone
in this direction that a single tender in a cotton-mill may have charge
of sixteen Northrop looms, and go to dinner leaving all at work. In case
that a thread breaks in any of them, the loom will stop of itself and
no harm will be done, the only loss consisting in the time during which
the wheels and levers have lain idle. A stop-motion at its simplest is a
fork through which the thread travels; as the thread moves forward, the
fork is bent downward extending a light coiled spring; should the thread
break, the spring instantly lifts the fork, which in rising stops the
machine.
Among the most noteworthy automatic machines are the presses which take
a continuous roll of paper, print both sides, cut it into leaves, fold
these, paste them at the back, and, if desired, sew them together and
attach a cover. Such a press stands for the union of several operations
once distinct; it argues great ingenuity, careful planning, with paper
exactly adapted to the stresses it must encounter, while the ink is of a
quick-drying variety.
[Illustration: Dexter feeding mechanism.
Dexter Folder Co., New York.]
The Dexter Feeding Mechanism.
Binding operations and a good deal of printing have to deal with
separate sheets of paper or card. To feed these to presses, folders or
binders was for many years a task for the hand. To-day the Dexter Folder
Company, of New York, in a diversity of machines supersedes this toil by
an ingenious imitation of manual movements. The uppermost sheet of paper
in a pile is for a moment held down at A by a rubber finger, during that
moment a small rubber roller B slightly buckles the sheet; at the same
time an airblast lifts the sheet from its pile; that done, all in a
twinkling, finger A rises and the sheet passes either into a press or a
folding machine. So nicely limited is the pathway for the paper that no
more than one sheet can pass at a time; if two or more sheets present
themselves, the feeding mechanism stops, bringing the press or folder to
a standstill. As each sheet passes from under the rubber fingers, the
table bearing the pile of paper is lifted by just one thickness of
paper.
Self-Acting Appliances in Metallurgy.
Mr. James Douglas, president of the Copper Queen Company, New York, thus
describes automatic devices in metallurgy: “The gold mill, with its
series of automatic operations, is the offspring of Californian
ingenuity. In it manual labor is almost entirely replaced by ocular
labor, for superintendence and not work is the function of the
mill-hands. The ore, dumped into the breakers, falls into large pockets,
whence it slides into automatic feeders, which supply the stamps with
regulated quantities. The free gold is partly extracted by liquid
mercury in the mortars, and by copper plates attached to their sides,
and partly on an apron of amalgamated copper plates, over which crushed
pulp flows as it issues from the battery screen. Automatic vanners
receive the tailings, separate the sulphurets, and discharge the waste.
When the power is water, the stream is divided to Pelton wheels, coupled
to the separate groups or even pieces of machinery. The absence of
intermediate running gear increases not only the sense, but the reality
of automaticity, and makes a skilfully arranged and thoroughly equipped
Californian mill one of the triumphs of modern mechanical metallurgy.”
Directive Paths.
An interesting field of ingenuity concerns itself with giving work the
right start and a simple path. A tear in a sheet of paper accurately
follows the line of a directive crease. Postage stamps, small as they
are, we readily detach from one another because perforations give
direction to the tearing strain. So the quarryman takes care to cut a
V-shaped groove in the rock he is to break, along which groove the break
takes its way. A bolt when over-strained will break in the thread,
whether this be the smallest section or not, because the thread is a
starting point for a parting. A rod of glass is divided with a slight
jar, provided that a groove has been filed in its surface. In all this
there is shown the importance of avoiding in a casting, or forging, such
minute cracks as under severe strain may lead to rupture.
The Pianola.
Within the past ten years automatic musical instruments have been much
improved and are now well established in public favor. Not a few
teachers of mark use them in their schools as a means of familiarizing
their pupils with the best music. All these instruments afford an
opportunity for expression on a performer’s part; the effects producible
by a practiced performer are remarkable, and give color to the
prediction that automatic music may have a parallel history with that of
the photograph, which has at last attained a truth and beauty which
bring it to a rivalry with the art of the painter.
From the educational series issued by the Æolian Company, New York, a
few notes from Schumann’s “Traumerei” are here given, together with
these notes as they appear on a music roll for the Pianola.
[Illustration: Schumann’s “Traumerei,” first notes.]
[Illustration: First notes of the “Traumerei” on a Pianola roll.]
A Pianola is operated by suction, through the exhaustion of air from a
bellows normally distended by springs as shown in 5 in the accompanying
illustration. The exhauster is operated by the pedal 1; the board 3,
with its small bellows, exhausts the air from 5 in the chest 7 by a
series of valves not shown in detail. When the air is pumped from 5 by
the motion of exhauster 3, this bellows collapses notwithstanding the
retractile spring 6. The exhaust condition may now operate upon any
chamber of the whole mechanism through trunk 7 and pipe 8. When a
perforation in a music sheet 16 passes over its corresponding duct in
tracker 15, air is admitted through tube 14, which relieves the
diaphragm in chamber 9, made of a very thin piece of leather, upon which
rests the stem of valve 11. Owing to the suction in chamber 9 this
diaphragm instantly raises and shuts the outer port 23 by means of valve
11, giving a free communication from pipe 8 through chambers 9 and 12,
to the striking pneumatic 13 which collapses, and through pitman 19 and
finger 20 strikes the key. As soon as the unperforated part of the
music sheet has passed over the hole 15 in the trackerboard, the flow of
air through pipe 14 is cut off and the pressure on the small diaphragm
in chamber 9 has ceased to be operative, and valve 11 immediately drops
and allows air to pass into striking pneumatic 13, through port 23, so
that pneumatic 13 and the key levers come back to their normal
positions.
[Illustration: Mechanism of Pianola.]
[Illustration: A
Before calling.
B
Calling the fifties.
C
Calling 58 from among the fifties.
Automatic telephone. Automatic Electric Co., Chicago.]
[Illustration: CALLING 6 ON THE AUTOMATIC TELEPHONE
AUTOMATIC ELECTRIC CO., CHICAGO.]
Automatic Telephones.
Much self-acting machinery employs electricity. By virtue of this
wonderful agent the Automatic Electric Company of Chicago instals
telephonic systems which enable a subscriber to connect himself directly
with any other subscriber, without the intervention of an operator at
the central station. As exemplified in large exchanges such as those of
Dayton, Ohio, and Grand Rapids, Michigan, the apparatus is complex in
its detail. If we take a small exchange, such as that of a village
with 100 instruments, we may readily understand the main principles of
the method. Let us suppose that No. 1 of our instruments is at the Post
Office, where the Postmaster wishes to call 58. With a finger he moves
hole 5 in the dial plate of his calling instrument (see the page
opposite 336) until it touches a protruding stud. Then he lets go, when
the dial returns to its original position. In returning it sends five
impulses to the central office where a vertical rod is lifted five
notches (see illustration, page 336.) He next moves hole 8 to the stud
and lets go. This time the rod turns through a considerable part of its
semicircle of motion. The instant its journey is at an end a tiny
metallic arm flies out and connection is completed with a wire running
to 58, ringing his bell. In case he is busy, a buzzing noise will be
heard in telephone No. 1. The switch mechanism which comes into play in
all this is simple. There are ten rows of switches, ten in each row: the
lowest row runs from 1 to 10, the next from 11 to 20, and so on. The
upward motion of the vertical rod in our example brought it to the
fifties; the turning motion decided that out of these fifties switch 58
should be connected with No. 1. When a conversation ends, hanging up the
receiver sends a current over both wires of the circuit so as to release
the selector rod, which returns to its original position.
If instead of a village we have a fairly large town, with an exchange of
1000 subscribers, a call for let us say 829 will involve taking to the
stud first hole 8, then hole 2, and lastly hole 9. And so on for
exchanges still larger. The pioneer inventor in automatic telephony was
the late Mr. Almon B. Strowger.
Chemical Triggers.
From triggers electrical we now pass to triggers chemical. A gun may be
charged with powder and remain for years perfectly at rest until a touch
on the trigger explodes the powder with tremendous effect. The example
is typical: nature and art abound with cases where a little energy,
rightly directed, controls energy vastly, perhaps infinitely, greater in
quantity. Often in a chemical compound the poise of attraction is so
delicate that it may be disturbed by a breath, or by a note from a
fiddle, as when either of these induces iodide of nitrogen to explode. A
beam of light works the same result with a mixture of chlorine and
hydrogen. One of the most familiar facts of chemistry is that a fuel,
such as coal, may remain intact in air for ages. Once let a fragment of
it be brought to flaming heat and all the rest of the mass will take
fire too. Iron has a strong affinity for oxygen, but for union there
must be at the beginning some moisture with the gas; the same is true of
carbon. A burning jet of carbon monoxide may be extinguished by plunging
it into a jar of dried oxygen. Gases from the throat of a blast furnace,
at a temperature of 250° to 300° Centigrade, are not inflammable in the
atmosphere until the air is moistened by steam or otherwise. Then in a
flash combustion begins in earnest.
In photography we meet with similar facts: violet rays may begin an
impression which yellow light can finish and finish only. Vulcanite is
transparent to red and infra-red rays which, although without action
upon an unexposed plate, are capable of continuing the action of actinic
rays upon a plate which has been exposed for a very short time.
Why Weather is Uncertain.
From photography let us pass to a glance at the atmospheric conditions
which greatly affect its work. The weather from day to day depends upon
factors so variable and unstable that prediction beyond twenty-four
hours is unsafe. “Suppose a stratum of air,” says Professor Balfour
Stewart, “to be very nearly saturated with aqueous vapor; that is to
say, to be just a little above the dew-point; while at the same time it
is losing heat but slowly, so that if left to itself it would be a long
time before moisture were deposited. Now such a stratum is in a very
delicate state of molecular equilibrium, and the dropping into it of a
small crystal of snow would at once cause a remarkable change. The snow
would cool the air around it, and thus moisture would be deposited
around the snowflake in the form of fine mist or dew. Now, this
deposited mist or dew, being a liquid, and giving out all the rays of
heat possible to its temperature, would send its heat into empty space
much more rapidly than the saturated air; therefore it would become
colder than the air around it. Thus more air would be cooled, and more
mist or dew deposited; and so on until a complete change of condition
should be brought about. In this imaginary case the tiniest possible
flake of snow has pulled the trigger, as it were, and made the gun go
off,--has altered completely the whole arrangement that might have gone
on for some time longer as it was, had it not been for the advent of the
snowflake. We thus see how in our atmosphere the presence of a
condensable liquid adds an element of violence, and also of abruptness,
amounting to incalculability, to the motions which take place. This
means that our knowledge of meteorological phenomena can never be
mathematically complete, like our knowledge of planetary motions,
inasmuch as there exists an element of instability, and therefore of
incalculability, in virtue of which a very considerable change may
result from a very small cause.”
In view of the inherent difficulties it is certainly creditable that the
predictions of the United States Weather Bureau should prove true six
times in seven, greatly inuring to the safety of mariners, of passengers
by lake and sea, and to the saving of crops under threat of destruction
by storms.