WORKING OF IVORY
of dividing up the tusk into workable material requires much skill and
thought, and also long practical experience. Beginning with the hollow
end of the tusk the cutter first removes that part of the base lacking
the requisite thickness, and then arranges the sections to be cut,
according to the progressive changes in its shape and solidity as he
advances in his task. This refers to rectangular work of all kinds.
Flat work should be cut on a line with the curve, as otherwise the
edges of the rings will show. The only waste in cutting should be along
the passage of the very thin blade of the saw, which is commonly from
15 to 30 in. in length, If to 3 in. in width, and but 1-50 in. in
thickness; it usually has five or six teeth to the inch.*
avoid waste of material, blocks should be centred in the lathe as near
to the convex side as possible. In rough-turning a block it should be
carefully adjusted in the lathe between the prong chuck and the poppet
head, its position being gradually changed by light taps on either end.
When it is revolving slowly the most prominent points are attacked by
the tool. As the cutting of large pieces involves very great waste,
blocks exceeding from 4 to 6 in. in length are rarely made. In cutting
rings from the hollow part of the tusk, the hollow is often plugged
with a piece of
♦Holtzapffel, op. cit., Vol. I, pp. 146-148.