Of Copying

82. The two last-mentioned sources of excellence in the work

produced by machinery depend on a principle which pervades a very

large portion of all manufactures, and is one upon which the

cheapness of the articles produced seems greatly to depend. The

principle alluded to is that of copying, taken in its most

extensive sense. Almost unlimited pains are, in some instances,

bestowed on the original, from which a series o
copies is to be

produced; and the larger the number of these copies, the more

care and pains can the manufacturer afford to lavish upon the

original. It may thus happen, that the instrument or tool

actually producing the work, shall cost five or even ten thousand

times the price of each individual specimen of its power.

As the system of copying is of so much importance, and of

such extensive use in the arts, it will be convenient to classify

a considerable number of those processes in which it is employed.

The following enumeration however is not offered as a complete

list; and the explanations are restricted to the shortest

possible detail which is consistent with a due regard to making

the subject intelligible.

Operations of copying are effected under the following


by printing from cavities by stamping

by printing from surface by punching

by casting with elongation

by moulding with altered dimensions