Chain

for engineers, is a sort of wire chain divided into links of an equal length, made use of for setting out works on the ground, because cord lines are apt to shrink and give way. There are several sorts of chains made use of in mensuration; as Mr. Rathbone’s, of two perches in length; others, one perch long; some of 1000 feet in length; but that which is most in use amongst engineers is Mr. Gunter’s, which is 4 poles long, and contains 100 links, each link being 7⁹²⁄₁₀₀ inches in length.