Wheel-lock of blued steel, with gold and silver inlay, and wheel-guard of tracery in thin gold. French, 17th Century. Collection of Major Farquharson.] The first lock was apparently a curved piece of metal in the shape of an S and pivoted in the centre, the upper point holding the match, the lower part, which was prolonged like the lever in the cross-bow, by its weight keeping the match from the pan till this lower part was compressed to the stock on firing. The next stage was the matchlock proper. This is the first lock where the mechanism is complete on a plate. The cock is kept back by a spring acting on the long arm of a lever, while fastened to the short end was a sear or trigger. The pan still projects on the side of the barrel, a principle seen in modern Eastern matchlocks. The next matchlocks had the pan fixed to and forming part of the plate; later matchlocks only vary in the shape of the plate. In the reign of William III. the plates are of the same size as the flint-lock, so that the locks could be changed when required. The matchlock was altogether in use for nearly 200 years, owing to its great simplicity and cheapness. There is a variation of the matchlock in which, by elaborate mechanism, the match is caused to descend on the priming with a snap-action. It is difficult to see the advantage to be obtained from this, as the match it would appear must have broken by contact with the pan, unless it may have taken the form of a stick of hard composition. The head of the match-holders in these locks is a short tube, which gives some probability to this theory, but there is no record to prove it.