longcase clocks use a seconds pendulum (also called a "Royal" pendulum) meaning that each swing (or half-period) takes one second. These are about a metre (39 inches) long (to the centre of the bob), requiring a long narrow case. The long narrow case actually predated the anchor clock by a few decades, appearing in clocks in 1660 to allow a long drop for the powering weights. However, once the seconds pendulum began to be used, this long weight case proved perfect to house it as well. British clockmaker William Clement, who disputed credit for the anchor escapement with Robert Hooke, made the first longcase clocks by 1680. Later the same year, Thomas Tompion, the most prominent British clockmaker, was making them too. Longcase clocks spread rapidly from England to other European countries and Asia. The first longcase clocks, like all clocks prior to the anchor escapement, had only one hand; an hour hand. The increased accuracy made possible by the anchor motivated the addition of the minute hand to clock faces in the next few decades. Between 1680 and 1800, the average price of a grandfather clock in England remained steady at £1 10s. In 1680, this was the amount paid by an average working family for a year's rent, so the purchase of clocks was confined to the relatively well-off. But by 1800 wages had increased enough so that many lower middle class households owned grandfather clocks. Modern longcase clocks use a more accurate variation of the anchor escapement called the deadbeat escapement. Description Traditionally, longcase clocks were made with two types of movement: eight-day and one-day (30-hour) movements. A clock with an eight-day movement required winding only once a week, while generally less-expensive 30-hour clocks had to be wound every day. Eight-day clocks are often driven by two weights – one driving the pendulum and the other the striking mechanism, which usually consisted of a bell or chimes. Such movements usually have two keyholes, one on each side of the dial to wind each one. By contrast, 30-hour clocks often had a single weight to drive both the timekeeping and striking mechanisms. Some 30-hour clocks were made with false keyholes, for customers who wished that guests to their home would think that the household was able to afford the more expensive eight-day clock. All modern striking longcase clocks have eight-day mechanical quarter chiming and full hour striking movements.