This art was carried to great perfection among the Romans ; and is of such importance at present, that it materially contributes to the perfection of many other branches in mechanics. The machine ought to be fixed in a light place, at a sufficient height to allow the turner to inspect his work, without endangering his eyes by the sudden separation of chips.
Previously to fixing the wood, bone, ivory, or metal, on the lathe, it ought to be rounded with a small hatchet, with a file, or with a plane; and the centres of the surfaces at each end should be ascertained : for this purpose, it will be advisable to lay the piece of wood upon a board; and, after opening a pair of compasses nearly to half the thickness of the piece, one of the legs must be attached to the board, and the point of the other brought into contact with one of the ends of the piece to be turned. Four equidistant arches must then be described at the circumference of such end, which should intersect each other within ; and, if these be accurately made, the point of intersection will be the centre. The middle of the opposite extremity ought now to be determined in a similar manner; a small hole be made in both; the points of the puppets inserted; and the piece firmly fixed, so that it may be easily revolved.
Next, the cord ought to be passed twice round the piece, and adjusted to the strap connected with the wheel: when the rest is placed as closely to the work as possible, the turner moves the wheel, by means of the foot-hoard; then presses a gouge, or other chis-sel, against the wood, in an horizontal direction ; and thus, by the steady, well-regulated application of his tools, gives it the requisite form. After having completely turned the work, it requires to be polished either with the skin of the Shark, the Rough Horse-tail, or other substance adapted to the nature of the material, thus manufactured.