INDUSTRIAL MACHINES.
One invention engenders another, or co-operates with another. None
lives, or stands, or dies, alone.
So, in the humble but extensive art of _broom-making_, men and women
worked along through ages binding with their hands the supple twigs of
trees or bushes, or of corn, by thongs, or cords, or wire, upon the
rudely-formed collar of a hand-smoothed stick, until the modern lathe
and hollow mandrel armed with cutters, the power-driven shuttle, and the
sewing machine, were invented.
The lathe and mandrel to hold the stick while it was cut was used
before, but it was long within the century that a hollow mandrel was
first invented, which was provided internally with cutting bevelled
knives, and into which the stick was placed, carried through
longitudinally, and during its passage cut smooth and finished. As broom
corn became the chief product from which brooms are made, it became
desirable to have a machine, after the corn had been scraped of its
seed, to size and prepare the stems in regular lengths for the various
sizes of brooms, and accordingly such a machine was invented. Then a
machine was needed and invented to wind the corn-brush with the cord or
wire and tie it in a round bunch, preparatory to flattening and sewing
it.
Then followed different forms of broom-sewing machines. Among the
pioneers was one which received the round bunch between two compressing
jaws, and pressed it flat. While so held a needle with its coarse thread
was forced through the broom above the binding and the cord twined
around it. Then a shuttle, also carrying a stout thread, was thrown over
the cord, the needle receded and was then forced through the broom again
_under_ the binding cord. Thus in conjunction with the shuttle the
stitches were formed alternately above and below the binding twine, the
holding jaws being raised intermittently for that purpose. As each
stitch was formed the machine fed the broom along laterally and
intermittently. By another ingenious device the cord was tied and cut,
when the sewing was completed.
It is only by such machines which treat the entire article from the
first to the last step, that the immense number of brooms now necessary
to supply the market are made. True it is that at first labour was
displaced. At one time seventeen skilled workmen would manufacture five
hundred dozen brooms per week.
They had reduced the force of earlier times by making larger quantities
by better processes. Then when the broom-sewing machines and other
inventions got fairly to work, nine men would turn out twelve hundred
dozen brooms per week. Thus, while the force was reduced nearly
one-half, the quantity of product was more than doubled. But as the cost
of labour decreased and the product increased, the product became more
plentiful and cheaper, the demand and use became greater, more
broom-corn was raised, more broom-factories started, and soon the
temporary displacement of labour was succeeded by a permanent increase
in manufacture and in labourers, an increase in their wages, and an
improvement in their condition.
Useful and extensive as is its use, the broom does not compare in
variety and wide application to the _brush_. The human body, cloth,
leather, metals, wood and grains, everything that needs rubbing,
cleaning, painting and polishing, meets the acquaintance of the brush.
Nearly a hundred species of brushes might be enumerated, each having an
especial construction for a particular use.
Although the majority of brushes are still made by hand, yet a few most
ingenious machines have been made which greatly facilitate and speed the
operation, and many mechanical appliances have been invented in aid of
hand-work. These machines and appliances, together with those which cut,
turn, bore, smooth, and polish the handles and backs, to which the brush
part is secured, have greatly changed and improved the art of
brush-making during the last fifty years.
The first machine which attracted general attention was invented by
Oscar D. and E. C. Woodbury of New York, and patented in 1870. As in
hand-making and before subjected to the action of the machine, the
bristles are sorted as to length and color. A brush-back, bored with
holes by a gang of bits, which holes do not extend, however, all the way
through the back, is placed in the machine under a cone-jointed plunger,
adapted to enter the hole in the brush-back. A comb-shaped slitted plate
in the machine has then each slit filled with bristles, sufficient in
number to form a single tuft. When the machine is started, the bristles
in a slit are forced out therefrom through a twisted guideway, which
forms them into a round tuft, and which is laid horizontally beneath a
plunger, which, descending, first doubles the tuft, and as the plunger
continues to descend, forces the double end down into the hole. The
plunger is supplied with a wire from a reel, turns as it descends, and
twists the wire around the lower end of the tuft, the wire being
directed in that way by a spiral groove within the plunger. The
continuing action of the plunger is such as to screw the wire into the
back. The wire is cut when the rotary plunger commences its descent, and
when the tuft is thus secured the plunger ascends, the block is moved
for another hole, and another set of bristles is presented for
manipulation. Brushes with 70 holes can be turned out by this machine at
the rate of one a minute.
Another most ingenious machine for this purpose is that of Kennedy,
Diss, and Cannan, patented in the United States in 1892. In this, brush
blocks of varying sizes, but of the same pattern, are bored by the same
machine which receives the bristles, and the tufts are inserted as fast
as the holes are bored. Both machines are automatic in operation.
_Street-sweeping machines_ began to appear about 1831 in England,
shortly after in France, and then in cities in other countries.
The simplest form and most effective sweeper comprises a large cylinder
armed with spiral rows of splints and hung diagonally on the under side
and across a frame having two or four wheels. This cylinder is connected
by bevelled gearing with the wheels, and in revolving throws the dirt
from the street into a ridge on one side thereof, where it is swept into
heaps by hand sweepers, and is then carted off. King of the United
States was the inventor.
A more recent improvement consists in the use of pneumatic means for
removing the dust that is caused by the use of revolving brooms or
brushes, such removal being effected by means of a hood that covers the
area of the street beneath the body of the machine, and incloses an air
exhaust, the sweepings being drawn through the exhaust mechanism and
deposited in a receptacle for the purpose, or in some instances
deposited in a furnace carried by the machine and there burned.
In cities having hard, smooth, paved streets and sufficient municipal
funds, the most effective, but most expensive way, has been found to
keep a large force of men constantly at work with hoes, shovels, brooms,
bags and carts, removing the dirt as fast as it accumulates.
_Abrading Machines._
One of the most striking inventions of the century is the application of
the sand-blast to industrial and artistic purposes.
For ages the sands of the desert and wild mountain plains, lifted and
driven by the whirling winds, had sheared and polished the edges and
faces of rocks, and cut them into fantastic shapes, and the sands of the
shore, tossed by the winds of the sea, had long scratched and bleared
the windows of the fisherman’s hut, before it occurred to the mind of
man that here were a force and an agent which could be harnessed into
his service.
It was due finally to the inventive genius of B. F. Tilghman of
Philadelphia, Pa., who, in 1870, patented a process by which common
sand, powdered quartz, emery, or other comminuted sharp cutting
material, may be blown or driven with such force upon the surface of the
hardest materials, as to cut, clean, engrave, and otherwise abrade them,
in the most wonderful and satisfactory manner.
Diamonds are abraded; glass depolished, or engraved, or bored; metal
castings cleaned; lithographic zinc plates grained; silverware frosted;
stone and glass for jewelry shaped and figured; the inscriptions and
ornaments of monuments and tombstones cut thereon; engravings and
photographs copied; steel files cleaned and sharpened, and stones and
marble carved into forms of beauty with more exactness and in far less
time than by the chisel of the artisan.
The gist of the process is the employment of a jet of sand or other hard
abrading material, driven at a high velocity by a blast of air or steam,
under a certain pressure, in accordance with the character of the work
to be done. The sand is placed in a box-like receptacle into which the
air or steam is forced, and the sand flowing into the same chamber is
driven through a narrow slit or slits in the form of a thin sheet,
directly on to the object to be abraded.
By one method the surface of the object is first coated with tinfoil on
which the artist traces his design, and this is then coated with melted
transparent wax. Then when the wax is hardened it is cut away along the
lines already indicated, and seen through the wax. The object now is
subjected to the blast, and as the sand will not penetrate a softened
material sufficient to abrade a surface beneath, the exposed portions
alone will be cut away. The sand after it strikes is carried off by a
blast to some receptacle, from which it is returned to its former place
for further use. Other means may be used in the place of a slitted box,
as a small or larger blow-pipe; but the driving of the sand, or similar
abrading material, with great force by the steam or air blast, is the
essential feature of the process.
_Emery_, that variety of the mineral corundum, consisting of crystalline
alumina, resembling in appearance dark, fine-grained iron ore, ranking
next to the diamond in hardness, and a sister of the sapphire and the
ruby, has long been used as an abradant. The Eastern nations have used
corundum for this purpose for ages. Turkey and Greece once had a
monopoly of it. Knight says: “The corundum stone used by the Hindoos and
Chinese is composed of corundum powdered, two parts; lac resin, one
part. The two are intimately mixed in an earthen vessel, kneaded and
flattened, shaped and polished. A hole in the stone for the axis is made
by a heated copper rod.”
However ancient the use of artificial stones for grinding and polishing,
nevertheless it is true that the solid emery wheel in the form that has
made it generally useful, in machines known as _emery grinders_, is a
modern invention, and of American origin.
In the manufacture of such machines great attention and the highest
scientific skill has been paid, first, to the material composing the
wheel, and to the cementing substances by which the emery is compacted
and bound in the strongest manner, to prevent bursting when driven at
great speed; secondly, to the construction of machines and wheels of a
composition varying from the finest to the coarsest; and thirdly, to the
proper balancing of the wheels in the machines, an operation of great
nicety, in order that the wheel may be used on delicate tools, when
driven at high speed, without producing uneven work, marking the
objects, or endangering the breaking, or bursting of the wheel.
Such machines, when properly constructed, although not adapted to take
the place of the file, other steel-cutting tools, and the grindstone for
many purposes, yet have very extensively displaced those tools for
cutting edges, and the grinding and polishing of hardened metals, by
reason chiefly of their greater convenience, speed, and general
adaptability. Not only tools of all sizes are ground and polished, but
ploughshares, stove and wrought-iron plates, iron castings, the inner
surfaces of hollow ironware, the bearings of spindles, arbours, and the
surfaces of steel, chilled or cast-iron rolls, etc.
In the great class of Industrial Mechanics, no machines of the century
have contributed more to the comfort and cleanliness of mankind than
those by which wearing apparel in its vast quantities is washed and
ironed more thoroughly, speedily, and satisfactorily in every way than
is possible by the old hand systems. When it is remembered how under the
old system such a large part of humanity, and this the weaker part,
devoted such immense time and labour to the universal washing and
ironing days, the invention of these machines and appliances must be
regarded as among the great labour-saving blessings of the century.
True, the individual washerwoman and washerman, and ironers, have by no
means disappeared, and are still in evidence everywhere, yet the
universal and general devotion of one-half the human race to the
wash-tub and ironing-table for two or more days in the week is no longer
necessary. And even for the individual worker, the convenient appliances
and helps that have been invented have greatly relieved the occupation
of pain and drudgery.
Among modern devices in the laundry, worked by hand, is, first, the
_washing-machine_, in which the principle is adapted of rolling over or
kneading the clothes. By moving a lever by hand up and down, the clothes
are thoroughly rubbed, squeezed and lifted at each stroke. Then comes
the _wringer_, a common form of which consists of two parallel rolls of
vulcanized and otherwise specially treated rubber, fitted to shafts
which, by an arrangement of cog-wheels, gearing and springs in the
framework at the ends of rolls, and a crank handle, are made to roll on
each other. The clothes are passed between the rollers, the springs
permit the rollers to yield and part more or less, according to the
thickness of the clothes.
Then the old-fashioned, or the new-fashioned mangle is brought into
play. The old-style mangle had a box, weighted with stone, which was
reciprocated on rollers, and was run back and forth upon the clothes
spread upon a polished table beneath. One of the more modern styles is
on the principle of the wringer above described, or a series of rollers
arranged around a central drum, and each having a rubber spring
attached, by which means the clothes are not subjected to undue pressure
at one or two points, as in the first mentioned kind.
Starch is also applied by a similar machine. The cloth is dipped into a
body of starch, or the same is applied by hand, and then the superfluous
starch squeezed out as the clothes are passed through the rollers.
But for hotels and other large institutions washing is now done by
steam-power machinery.
It is an attractive sight to step into a modern laundry, operated with
the latest machinery on the largest scale. The first thing necessary in
many localities is to clarify the water. This is done by attaching to
the service pipe tanks filled with filtering material, through which the
water flows before reaching the boiler. The driving engine and shafting
are compactly placed at one end or side of the room, with boilers and
kettles conveniently adjacent. The water and clothes are supplied to the
washing-machine, and operated by the engine. Steam may be used in
addition to the engine to keep it boiling hot, or steam may be
substituted entirely for the water.
The machine may be one of several types selected especially for the
particular class of goods to be washed. There is the dash-wheel,
constructed on the principle of the cylinder churn; the outer case being
stationary and the revolving dash-wheel water-tight, or perforated,
which is the preferred form for collars and cuffs. In place of the
dash-wheel cylinders are sometimes used, having from sixty to seventy
revolutions a minute. Another form has vibrating arms or beaters, giving
between four hundred and five hundred strokes a minute, and by which the
clothes are squeezed between rubbing corrugated boards. The rubbing
boards also roll the clothes over and over until they are thoroughly
washed. In another form a rotating cylinder for the clothes is provided
with an arrangement of pipes by which either steam, water or blueing can
be introduced as desired, into the cylinder, through its hollow
journals, so that the clothes can be washed, rinsed, and blued without
removal from the machine.
Another type has perforated, reciprocating pistons, between which the
clothes are alternately squeezed and released, a supply of fresh water
being constantly introduced through one of the hollow cylinder journals,
while the used water is discharged through the opposite journal; and in
still another the clothes are placed in a perforated cylinder within an
outer casing, and propeller blades, assisted by other spiral blades,
force a continuous current of water through the clothes.
In ironing, hollow polishing rolls of various sizes are used, heated
either by steam or gas. The articles to be ironed are placed in proper
position upon a table and carried under and in contact with the rolls.
Or the goods are ironed between a heated cylinder and a revolving drum
covered with felting, and the polishing effected by the cylinder
revolving faster than the drum. Ingenious forms of hand-operated ironing
machines for turning over and ironing the edges of collars, and other
articles, are in successful use.