pair of Compasses, a mathematical instrument for describing circles, measuring figures, &c.

The common compasses consist of two sharp-pointed branches, or legs, of iron, steel, brass, or other metal, joined at top by a rivet, whereon they move as on a centre.

The principal perfection of this, as of all other compasses, consists in the easy and uniform opening and shutting of their legs; one of which may be taken out, in order to make room for others.

There are now used compasses of various kinds and contrivances, accommodated to the various uses they are intended for.