Elliott Bros. ‘The Ashdown Rotoscope’

rare scientific instrument produced by the Eliott Brothers Ltd of London which gives the optical effect of ‘slow motion’ on high speed moving objects. If the object under test executed a recurrent motion, then it is possible to view the object as stationary, or nearly so, by adjusting the time interval accordingly. A governor can be made to run between 50 and 125 RPM and thus by multiplying this with the gear ratio, the shutter speed may be calculated. The Rotoscope was used to examine the workings of a machine running at a known speed, and determine speed variations. The paint on the front cover is chipping off, otherwise in perfect and working condition, original fitted wooden box. Ex-Naylor Collection.