Browse Items (10 total)

“When wound and activated, the instrument produces a whirring noise to eliminate the extraneous sounds from one ear so that the hearing of the other ear can be effectively tested.”


Old tag: H. Merriman MD. M. 1984-062

Wooden box with strap handle.  Note:  “The box is handmade and the slots and grooves for the instruments hand carved” Includes:  Metallic tablet + Razor Strap  G. Saunders 1852 Brass nested weights  Hook scale CHATILLON’S IMPROVED SPRING…

Patents: 1913-1914

On Receiver:                  Licensed US patent office 12030                 726A Headband“Y” ended connecting wire

1 pair A/O 1/12 -10K Pat Pend.
Machine engraved.

For ophthalmic lens power measurement.

Old tag: Unknown m-1976 037 #42991

Contains:Old tubing  3 way valve  Graduated Glass tube  2 metal canisters by GP Pilling + Son Co, Phila PA Pat March 4th, 13(?)

Descriptive card: "'U' type entirely enclosed by a small metal housing and held in place by melted wax. A table clamp secured this portable instrument. The small scale was hard to read."

RIEGER BOWLES, Patent 1671936