1. Trifling as the manufacture of buttons may appear, there are few
which include a greater variety of operations. The number of
substances of which they are made is very great, among which are
gold, silver, various alloys of copper, steel, tin, glass,
mother-of-pearl, bone, horn, and tortoise-shell, besides those which
consist of moulds of wood or bone, covered with silk, mohair, or
similar materials.
2. In making gilt buttons, the _blanks_, or bodies, are cut from
rolled plates of brass, with a circular punch driven by means of a fly
wheel. The blanks thus produced, are planished with a plain die, if
they are intended for plain buttons; or with one having on it an
engraved figure, if they are to be of the ornamental kind. In either
case, the die is usually driven with a fly press.
3. The shanks are next placed on one side of the proposed button, and
held there temporarily with a wire clasp. A small quantity of solder
and rosin having been applied to each shank, the buttons are exposed
to heat on an iron plate, until the solder shall have melted. The
shanks having been thus firmly soldered on, the buttons are turned off
smoothly on their edges in a lathe.
4. The buttons are next freed from oxyde, by immersing them in diluted
nitric acid, and by friction in a lathe. They are then put into a
vessel containing a quantity of nitric acid supersaturated with
mercury. The superior attraction of the copper for the acid, causes a
portion of it to be absorbed; and the mercury held in solution by it,
is deposited on the buttons, which are next put into a vessel
containing an amalgam of mercury and gold.
5. The amalgam is formed by melting the two metals together, and
afterwards pouring them into cold water. The composition having been
put into a bag of chamois leather, and a part of the mercury pressed
through the pores, the remaining portion is left in a condition
approaching the consistency of butter, and in a fit state for use.
Before the buttons are put into the amalgam, a small quantity of
nitric acid is added.
6. The buttons having been covered with the amalgam, as before stated,
the mercury is discharged, that the gold may adhere directly to the
brass. This object is effected by heating the buttons in an iron pan,
until the amalgam begins to melt, when they are thrown into a large
felt cap, and stirred with a brush. This operation is repeated several
times, until all the mercury has been volatilized. The whole process
is finished by again burnishing them, and putting them on cards for
sale.
7. White metal buttons are made of brass alloyed with different
proportions of tin. They are cast, ten or twelve dozens at a time, in
moulds formed in sand, by means of a pattern. The shanks are placed in
the centre of the moulds, so that, when the metal is poured in, they
become a part of the buttons. The buttons are next polished in a
lathe, with grindstone dust and oil, rotten stone and crocus martis.
They are then boiled with a quantity of grained tin, in a solution of
crude red tartar or argol, and lastly, finished with finely-pulverized
crocus, applied with buff leather.
8. Glass buttons are made of various colors, in imitation of the opal
and other precious stones. While manufacturing them, the glass is kept
in a state of fusion, and a portion of it for each button is nipped
off out of the crucible with a metallic mould, somewhat similar to
that used for running bullets, the workman having previously inserted
into it the shank.