Some stones, as “Bath stone” can be cut with a common toothed saw,
and are but little harder than chalk; others, as marble, Portland
stone, &c., require to be cut with a flat blade of iron stretched in
a frame and having a supply of sand and water. A man sits in a shed
having this heavy saw suspended from two poles, and balanced by a
piece of stone swung over a pulley; he alternately pushes and pulls
the frame, allowing the water to trickle into the seam as it forms,
the sand being rubbed between the edge of the saw and the stone as
the saw is moved backwards and forwards, slowly cutting the stone
(see illustration). By this slow and tedious process building stones
are cut into squares, slices, slabs, or any other form required.
Granite is too hard for even this slow process, and after the pieces
are chosen as nearly as can be got of the size and shape required,
they are worked with a heavy iron pick (fig. 1), which at each blow
strikes off a little piece not bigger than a pea, by which method the
stone is shaped into the form required. Smaller cuttings of stone for
building purposes, such as carvings, &c., are formed by the mallet
and chisel (fig. 2), the work being finished with a rasp or steel
scraper.