Description

UNUSUAL HORIZONTAL DIAL, English, 1789, signed “Onions, 1789, Lat. 51°30′.” The 3″ x 4″ (8 x 10 cm) brass dial is set into a tabernacle-shaped fruitwood carrying case, complete with early handwritten equation of time table. The brass dial itself is beautifully executed, the folding gnomon pierced and engraved with floral design, the chapter ring divided every five minutes, the inset compass surrounded by engraved vines and flowers, the glazed compass itself with engraved brass compass rose and finely cut needle. To the west of the fleur-de-lys North point is an engraved “V” and “27,” indication of the point of magnetic variation. (In fact, consulting a plot of variation vs. time and place, we find, for London, the declination in 1780 was 23° West and heading further west at about 0.15 degrees per year ‹ as it had been doing for the previous 200 years. Thus Onions, in 1789, could have anticipated a variation of 27° about 20 years later, and constructed a dial made to last. In fact, the actual variation slowed down and, reaching a peak about 1810, then reversed direction, and now approaches 0° in London. It never made it close to 27°!) Condition of the dial is very fine, noting a crack and water (?) damage to the wood base. The maker, presumably Peter Onions, is listed in Loomis as a clockmaker working in Brosley c.1760. He gave his own distinctive, rather elegant design to the dial and its decoration. The overall shape, in fact, mimics that of a standing clock! Most unusual.