Charles McDowall, St. John’s, Wakefield.

A very rare mid-19th century English skeleton clock with helical gearing by Charles MacDowall, Wakefield. The high-quality month running movement has shaped plates, four large posts screwed with collets front and rear, a silvered dial, helical gearing, a dead-beat escapement and a triangular shaped brass pendulum.

The engraved silvered dial has Roman numerals for the hours, two nicely cut steel hands and is elaborately engraved in the center.

The four wheel helical geared time-only train has heavy brass wheels with rounded collets, an unusually elongated fusee, steel screwed end stops on the backplate and a caliper style steel dead-beat anchor that encompasses 6 teeth of an 18-tooth escape wheel. The crutch is fastened by a screwed collet to the anchor arbor and, unlike most clocks, comes down inside the backplate, encircles the next arbor and engages with the pendulum by a steel pin through a cut-out slot in the back plate. The shaped pendulum is suspended from a screwed beat adjustment by a steel suspension spring, is triangular shaped and has a rounded brass bound bob with the rating nut located above.

Charles MacDowall was apparently the first in England to produce a series of clocks using this system of gearing. Although the great mechanical advantages of helical gearing were widely known by all those working within the engineering fields, clockmakers tended to rely on the traditional methods because of the great difficulty in making the helical shaped wheels and pinions to the necessary tolerances. MacDowall ingeniously retooled and created a line of high quality skeleton clocks, all seemingly different from each other, which took advantage of this method of gearing. Charles MacDowall is listed in Britten’s as working 1835-1872.

For additional information on MacDowall see:

Royer-Collard, pgs. 61-63 and for a similar clock see Fig. 3-50.

Derek Roberts, ‘British Skeleton Clocks’, and pgs. 171-174.