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From the foundery we proceed, across the open
yard, to the smithy, a large, lofty, well proportioned
apartment, containing two enormous steam-hammers,
the speed and consequent impetus of which can be
modulated by a very easy application of manual
force, at the pleasure of the operator, so that they
can be made either to rise and fall as slowly as the
maces of Gog and Magog on the great bell of Saint
Dunstan's, or to impinge upon whatever is objected
to their descent with a velocity which almost mocks
the eye. In this apartment and its adjunct forge
there are no less than eighteen scithies, the bellows
of all which are worked by the ubiquitous power of
the engine, with anvils of all manners and sizes in
due proportion, and sturdy operatives plying them with tranquil
and regulated industry, worth five times
the amount of human force exerted unequally and
impulsively, by fits and starts.
Immediately adjoining the smithy, is the engine
and machine-shop, and on the same floor the large
lathe-room containing four enormous surface lathes
and two turning lathes, for drilling, boring, turning, .
and finishing both circular and horizontal surfaces.
From this point, we shall proceed to the saw works,
preferring to take each separate department of
work by itself from the commencement to the end,
rather than to adhere to the precise order and position
of the several rooms. as situated in the building.
The first room devoted to this branch of manufacture,
which is a very considerable and important
item in the business of Messrs. Hoe & Co., the
annual sales amounting to not less than 140.000 dollars,
in circular-saws, mill-saws, pit-saws, and crosscut-
saws, for all parts of the country, is known as
the saw-shop.
This operation is performed by the vertical descent of a ponderous
arm of iron, terminating in a
cutter of the form of the notch to be made in the yet
soft and smooth edge of the circular plate, which is
made by the same power to revolve horizontally
upon an axis placed at such distance from the impinging
weight as the depth of the notch to be cut
requires, and traversing at a rate so timed in unison
with the descent of the cutters as to render the series
of teeth perfectly continuous and equal; each blow
of the cutter forming the interval between two teeth,
and each full revolution of the plate completing a
circular saw. In the same way is effected the teething
of the straight saws, the motion being a direct
sliding action in a forward line, instead of a rotatory
movement.
This process is effected by heating the metal in
charcoal furnaces to a white incandescent glow, and
then cooling it by immersion in baths of oil and other
drugs, the combination of which is, we believe, a
secret. This done, the saws are ready for grinding,
which is effected in a special apartment of the main
building-the fiat, straight saws by hand application
to a series of powerful grindstones, driven at a regular
speed by gearings worked from the engine and
the circular saw, by a very curious and effective
patent machine, peculiar to this establishment, and
invented by Mr. Hoe himself.
The new machine causes the great circular plate
to revolve vertically on its access, while a "pad" to
which is applied some sharp, detergent mineral powder,
is moved forcibly over its surface with a
triple action.
In the first place, the pad itself is made to revolve'
with great velocity against the circular plane, in a
direction perpendicular to its line of motion. In the
second place, it is driven forward against it horizontally
with a force increasing or diminishing, in proportion
as it may be desirable to render the saw blades
thicker or thinner in any particular part of the
circumference. It is usual to leave them thicker at the centre,
and to grind them away gradually toward
the circumference.
This machine is one of the special wonders and ornaments
of the establishment.
It will not be amiss here to add, that with the improvements
of their manufacture the demand for circular
saws is continually on the increase; and that a
single house is in the habit of taking regularly six of
these powerful tools weekly from the Messrs. Hoes'
establishment. Returning hence to the leading and principal feature
of these works, the manufacture, namely, of all
the various instruments and appliances for the art
imprimatorial, we are next ushered into the iron
planing and cutting engine rooms, for the cutting the
cogs of engine wheels, and finishing the surfaces of
whatever portions of the machinery must be brought
to a smooth and polished face. This is done by the
propulsion of the pieces of metal so to be planed, in a
horizontal and longitudinal direction against cutting
edges, which again move horizontally across the
moving planes, and are pressed downward on them
vertically, so as to bring the planing to the requisite
depth. The abraded portions are thrown off from
the surface, of cast iron in a sort of scaly dust, from
wrought iron in long, curled shavings, and the planes'
can be wrought up to almost any desirable degree of
finish and smoothness.
The cutting engine for the formation of cogged
wheels, bears some relation to that for the teething
of saws, the cutter impinging downward, with an action
in some degree intermediate between that of sawing
and filing, upon the exterior circumference of the
circular wheels, which revolve on their axis under
them in a rotation so regulated to the fall of the
striker as to insure absolute equality in the width of
the cogs or projections.
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