Darton barometer altimeter with finely engraved and silvered brass 4¼” dial, the outer altimeter scale 0–7,000ft, the inner barometric scale 24–31 inches of mercury.  Upper portion marked “Compensated,” “No. 851,” the lower with maker’s legend “F. Darton & Co, London.” Blued-steel pointer, rotating bezel with fine spur index, set beneath bevelled glass. Heavy duty 2″ deep brass case with block-mounted swinging arm and suspension ring, the rear with compensation adjustment port and screw set at 4 o’clock, broad arrow military ordnance mark to centre.

These antique aneroid instruments may be considered scarce.  Few survive, and this Darton altimeter remains in ‘as found’ original condition – sensitivity and transition remain excellent. It is most likely that the War Department issued this to the Army as opposed to the Royal Navy, with possible users being the Royal Engineers. A fine original instrument for the collector.

Banfield, Edwin, Barometer Makers and Retailers, 1660-1900 records Francis Darton & Co as working from various addresses in London from 1834 onwards, and the company existed up until the 1990s.

Dimensions: 4¼” diameter x 2″ deep

Stock No: BA0291

Price: £225