Anchor escapement to only 4°-6°. In addition to the improved accuracy due to isochronism, this allowed clocks to use longer pendulums, which had a slower 'beat'. Lower air drag meant they needed less power to keep swinging, and caused less wear on the clock's movement. The anchor also allowed the use of a heavier pendulum bob for a given drive force, making the pendulum more independent of the escapement (higher Q), and thus more accurate. These long pendulums required long narrow clock cases. Around 1680 British clockmaker William Clement began selling the first commercial clocks to use the anchor escapement, tall freestanding
Watch Nevertheless, the craftsmanship of mechanical watches still attracts interest from part of the watch-buying public, especially among the watch collectors. Skeleton watches are designed to leave the mechanism visible for aesthetic purposes. A mechanical movement uses an escapement mechanism to control and limit the unwinding and winding parts of a spring, converting what would otherwise be a simple unwinding into a controlled and periodic energy release. A mechanical movement also uses a balance wheel together with the balance spring (also known as a hairspring) to control the motion of the gear system of the watch in a manner analogous to