Early in the sixteenth century the culverin gave place to the serpentin, which, in turn, was slightly modified and became the famous match-lock. To fire the culverin, the attendant had to stand with a lighted match over the touch-hole, but in the serpentin the igniter was gripped by a lever which descended into the flash-pan. The match-lock had the flash-pan covered by a lid, which gave a certain amount of protection to the sparking action in wet or windy weather. The next innovation was the wheel-lock, a weapon which possessed a metal disc provided with a serrated edge. By winding up the disc and using the trigger to release it, it was possible to make the serrated wheel fly round at a considerable rate. As the rough teeth revolved, they scraped against a piece of flint and so produced sparks, which flew into the flash-pan and caused ignition of the powder charge. The system was certainly an ingenious one, but the cost of making these elaborate pieces of mechanism militated against the general use of the wheel-lock for army purposes. After the wheel-lock came the flint-lock. This style of arm possessed a hammer which was provided with a "flint-cock." When released, the flint and the steel came into violent contact, and produced sparks which flew into the touch-powder. The flint-lock was commonly used in the Netherlands, and was brought to England by William of Orange, remaining in use until 1840.[13] Specimens are obtainable for private collections, but early patterns are of some rarity and fairly expensive.