Dating brass dial grandfather clocks
However, it was the invention of the anchor escapement by William Clement, an Englishman in 1671, using a "seconds" pendulum, 39 inches long and vibrating through a small arc, that cleared the way for making the weight and pendulum tall case clock practical.
This invention plus another, the dead beat escapement, invented by George Graham in 1715, brought about the basic clock design that few could improve on for nearly two centuries.
So went the lyrics of a song , written by Henry Clay Work, a songwriter not a clockmaker, in 1876, that was to change how America looked at tall-case clocks.
The name "grandfather clock" didnt appear until Work wrote the song, so none of the men who actually made the clocks ever knew them by that name.
Fundamentally, these clocks consisted of four parts: The weight, the source of power; the train, which transmitted the downward pull of the weight into the rotary velocity; the escapement, which transmitted the rotary velocity of the train into intermittent--or periodic--motion; and the pendulum, the controlling element associated with the intermittent motion of the escapement.
The theory behind this was that the force of a weight is constant, while the force of spring may vary with its tension.
The cost of a typical grandfather clock in the 1780s was .50, and few were produced compared to other furniture forms in the 18th century.
Until the Revolutionary War, tall case clocks closely resembled their English cousins.
Therefore, theres nothing to distinguish the Colonial American long-case clock from its European cousin.But when the war ended in 1783, casemakers began introducing their own styles which were firmly established by the end of the century.Those made to order in the 18th century were of superior craftsmanship and design.From the early days, two distinct schools of clockmaking emerged, one centered in Philadelphia, the other in Boston.
Those of the Philadelphia School spread from New York down the Delaware Valley to Virginia and Carolina.The power to move the cogs and wheels of this type of clock was produced by heavy weights that had to be wound up daily.The mechanism was encased in a wooden cabinet with a dial that told the time.In England, he would have depended on brass casters, on dial-engravers, on makers of pinion wire, and certainly on case-makers.