An interesting brass revolution counter in original transport case c1880

High quality brass revolution counter, the outer largest 100-toothed wheel marked 0-100 with stations on the 10, and the next two subsidiary wheels displaying a range each from 0-10.

This counter operates on the pin and slot principle, ie a pin appended to the underside of each wheel causes the next to move as the pin engages with and passes the slot formed in that wheel. The prime wheel moves the secondary wheel on by one (hundred) each time it completes 100, and the second wheel moves the third wheel on by one (thousand) each time that second wheel completes 1,000. Thus these three wheels enable revolution counting up to 10,000 revolutions. A sliding bar allows the counter to be disengaged from the shaft being measured whilst in use.

Contained within its original leather over wood, imperial purple silk and velvet lined travel case, snap catch on button release.

Condition: Remaining in completely original condition and working correctly.

Comments: This item has been the subject of extensive research, but though related instruments have been identified, nothing has yet been found that could be described as being similar. However, the quality of manufacture and the design are reminiscent of the revolution counter patented in 1877 by M. Sainte in France, see image below.

Analysis would suggest this indicator or counter was designed for use at an application where higher shaft revolutions were found – it would seem to be capable of recording shaft rotations up to 10,000rpm. It would be used in association with a form of chronograph or stop watch.

An extremely unusual and high quality instrument, almost certainly made in France.