Page:On the economy of machinery and manufactures - Babbage - 1846.djvu/193

Rh superior finish, at 1s. 9d. per dozen. One circumstance which has produced this economy in the manufacture is, that the lathe on which these knobs are finished is now turned by a steam-engine; so that the workman, relieved from that labour, can make them twenty times as fast as he did formerly.

(206.) The difference of price of the same article, when of various dimensions—at different periods in the same country—and in different countries—is curiously contrasted in the annexed Table.

The price of silvering these plates is twenty per cent. on the cost price for English glass; ten per cent. on the cost price for Paris plates; and twelve and a half on those of Berlin.

The following table shews the dimensions and price, when silvered, of the largest plates of glass