Small hand-sized spectroscope with eyepiece and port in black, velvet-lined box. Approximately swan-neck shaped with slit at end of narrower section; black painted metal with brass eyepiece; screw hole on side for pillar mounting. Inscribed in…
Device for displaying ultrasonic timing pulses; osciliscope technology; customised for use with ultrasonic probes; serial number on back B.661. Great Britain Patent number 696920