A SMALL ANTIQUE ANEROID POCKET BAROMETER & ALTIMETER BY DENT OF LONDON. IN GOOD CONDITION, IN FULL WORKING ORDER AND CONTAINED IN AN OUTER LEATHER CASE. AN EXTREMELY RARE & EARLY INSTRUMENT CIRCA 1860s WITH BY A VERY PRESTIGIOUS MAKER. I HAVE NEVER SEEN ANOTHER SIMILAR POCKET BAROMETER BY THE FAMOUS DENT FIRM. Diameter 4.5cm (1 3/4″) Depth 1.7cm (11/16″). The dial is silvered with fine black lettering and carries a fine blued pointer. It bears the engraved signature ” Dent, 61 Strand, London”. It is also engraved with 3 weather conditions ” Rain, Change, Fair” and also “Compensated” (for temperature). There are 2 scales on the dial. The inner ring reads from 23″ to 31″ registering the atmospheric pressure. The outer ring reads from 0 to 8,000 feet registering the altitude. The front bezel rotates to adjust the recording pointer. The instrument has a patinated brass pocket watch shaped case in good condition. The reverse has a small hole enabling access to the calibration screw. The glass is bevelled and appears to be original with no damage. Overall in good condition with a very clean dial. The barometer is in full working condition and readily passes the’plastic bag’ pressure test. The bezel rotates (a little stiffly). The case is covered in leather with bit of wear & loss mainly around the hinge. The case closes firmly and opens by pressing the brass button. Internally the case is covered in green velour and silk linings in excellent condition.