in the manege, a chain of iron made fast to the upper part of the branches of the bridle, in a hole called the eye, and running under the horse's beard. It consists of three parts; the hook fixed to the eye of the branch, the chain of links, and the two rings or mules. A large curb, provided it be round, is always most gentle; but care must be taken that it rest in its proper place, otherwise the bit-mouth will not have the effect that may be expected from it.