For sale an early Nineteenth Century Miners Dial or Surveyors Dial by Dollond of London.
Comprised of a large five inch compass with a two tiered engraved and silvered dial. The outer scale is graduated through three hundred and sixty degrees whilst the secondary lower tier is graduated in ninety degrees between each main compass point, it is also engraved with a superbly executed star motif to the centre of the dial. The steel pointer moves within the lower section allowing for more accurate reading of the outer dial and a brass locking bar is fitted to the central spindle to lift the mechanism whilst in transit and stop it moving freely when not in use.
A brass arm graduates out from the North and South points of the compass and both contain a hinged sight (or alidade) at each end to allow the user to line up an object for surveying. The underside of the instrument has a brass ferrule for attaching a staff or a tripod for steadying purposes.
When not in use, a lid is provided to protect the compass rose, the placement of which has the effect of locking the compass pointer. The alidade would then be folded down upon the lid to make it as compact as possible. It too has a scale provided in links and states above, “Diff of Hypo & Base”.
Dollond, were set up in Hatton Garden in 1750 by Peter Dollond with his father John joining him shortly after. John Dollond’s invention of the achromatic lens (although bitterly disputed) led to his award of the Copley Medal by The Royal Society in 1758 and following this success, Dollond moved to The Strand where the company was appointed optician to George III and the Duke of York in 1761.
Following the deaths of John in 1804, Peter Dollond took his nephew George Huggins into partnership and after a change in surname, the company became P&J Dollond until Peter’s death in 1820, the same year that they were jointly made opticians to George IV.
The company continued its association with royalty and went on to win a Great Exhibition Medal in 1851, a year before George’s death. His nephew (also George) succeeded in the ownership until his death in 1866 wherafter his son William continued to run the business. William was the final Dollond family member to run the company, finally selling out to a former employee of the company, JR Chant in 1871. Chant continued to use the company name until was acquired by James Aitchison in 1927 whereafter it became Dollond & Aitchison. In 2009 it became part of Boots the Opticians.
A very fine example of a miners dial by one of the most noted London scientific instrument making companies.