Modern longcase clocks use a more accurate variation of the anchor escapement called the dead beat escapement. The deadbeat form of the anchor escapement was initially used only in precision clocks, but due to its superior accuracy its use spread during the 1800s to most quality pendulum clocks. Most pendulum clocks made today use it.
Most of a longcase clock's height is used to hold the long pendulum and weights. The two chains attached to the weights. The lack of winding holes in the dial or clock face show this to be a 30-hour clock.
Traditionally, longcase clocks were made with one of two types of movements, the eight-day and one-day (30-hour) movements. Today we have 31 day and quartz movements in some longcase or grandfather clocks. Eight-day clocks are often driven by two weights, one driving the pendulum and the other the striking mechanism. Such movements usually have two keyholes on either side of the dial or clock face 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. Cable clocks are wound by inserting a special crank (called a "key") into holes in the clock's face and turning it.
Others are chain-driven and have weights suspended by chains that wrap around gears in the clock's mechanism. To wind a chain-driven longcase clock, the end of each chain is pulled, lifting the weights. In the early 20th century, quarter-hour chime sequences were added to longcase clocks.
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