A super silver, pocket barometer with an engraved steel face. It can be dated to London, 1888 and comes with the original leather case.

It measures approx 5cm in diameter.

This is an unusual and rare timepiece made by Mensor.

It has multicolour tachymeter scales on both dials and a devolving scale on the rear dial which also displays reverse seconds. The dials represent speed in any unit once any object or phenomenon bypasses that unit of length; for example for the first four minutes, the reverse scale shows speeds of up to 200 units per hour (e.g., km/h or mph) when the object travels through one unit of length in the first approximately 18 seconds; the reverse indicator points to the red scale to read red numbers for the first minute, black for black numbers in the second minute, and so forth until one refers to the front dial for the continuation of observation past four minutes. Observation may occur up to 20 minutes for determining speeds as low as 3 units per hour.

It is in excellent condition and measures approx 5cm in diameter. In the original fitted box.