Joseph Merlin’s Band Clock

This Joseph Merlin Band Clock built by John Mills is an example of a design popular with model engineers. J. G. Wright describes making this clock in a book from Rite Time. In the catalogue John Wilding describes it as a “most unusual and complicated clock and is not for the inexperienced clockmaker.” However, many model engineers will not be daunted by the need to machine an 8tpi worm or making the rotating bands that replace the dial of a conventional clock. A number of special jigs and tools also have to be made.

Joseph Merlin was an inventor born in 1735. Among other things he invented roller skates.

Time is indicated on two separate bands, one for hours and one for minutes, rotating around a centre arbor. The minute hand revolves with the arbor held in place by a friction bow spring. The hour band is a loose fit on the centre arbor and is indexed by 12 pins that connect with a detent at the bottom of the band. When it is time to change the hour the minute band has a pin that engages with a pivoted arm on the front column, and the arm also engages with one of 12 pins on the hour band.

The clock has a conventional fusee and spring barrel, although in this clock the fusee revolves clockwise rather than anti-clockwise as is usual, and it has a left-hand groove of 16 turns. Unusually, the centre wheel turns the escape arbor by a worm. The centre arbor turns once an hour, and all arbors run in jewelled pivots. It has a deadbeat escapement and runs for eight days. The base of the clock is an integral part of the clock.

In addition to the bands there is a conventional dial on one side of the clock and a date calendar on the other.

A fascinating and most attractive clock.