Estimated Date: 1900
Description: 7“h 6“d drum on very heavy cast iron stand. A 3.5“x 2“x 1.25” brass box contains the gear mechanism. There is a winding key and a fly wheel. Drum turns on gear at bottom connected to gear on box bottom with a replacement o ring. On one leg is a rod with adjustable connectors and two air actuated diaphrahms with original needles to attach to physiologic recording device..Additional recording deviices of the type shown here could be attached to broaden its range of measurements.
Reference 1: 133