TRIER, or PROVER, a machine used in the cloth manufactory, to stretch out the pieces of cloth, stuff, &c. or only to make them even and set them square.

It is usually about 4 feet high, and for length exceeds that of the longest piece of cloth. It consists of several long square pieces of wood, placed like those which form the barriers of a manege; so, however, as that the lower cross pieces of wood may be raised or lowered as is found requisite, to be fixed at any height by means of pins. Along the cross pieces, both the upper and under one, are hooked nails, called tenter-hooks, driven in from space to space.

To put a piece of Cloth on the TENTER. While the piece is yet quite wet, one end is fastened to one of the ends of the tenter; then it is pulled by force of arms towards the other end, to bring it to the length required; that other end being fastened, the upper lift is hooked on to the upper cross-piece, and the lowest lift to the lowest cross-piece, which is afterwards lowered by force, till the piece has its desired breadth. Being thus well stretched, both as to length and breadth, they brush it with a stiff hair brush, and thus let it dry. Then they take it off; and, till they wet it again, it will retain the length and breadth the tenter gave it.