Spencer no. 393 voltage transformer for model 353 universal microscope lamp
Date: circa 1940
Inventory Number: 2009-1-0081
Classification: Transformer
Subject:
Maker: Spencer Lens Company (1895 - 1945)
Maker: Triplett (founded 1904)
User: William Alexander Jackson (1905 - 1964)
User: William H. Bond (1915 - 2005)
User: Houghton Library, Harvard University (founded 1942)
Cultural Region:
Dimensions:
transformer without cord: 9.3 × 12.6 × 19 cm (3 11/16 × 4 15/16 × 7 1/2 in.)
box: 9 × 15.2 × 21.7 cm (3 9/16 × 6 × 8 9/16 in.)
Accessories: microscope lamp (2009-1-0072)
Bibliography:
Spencer Stereoscopic Microscopes
Description:
The transformer is Spencer model 393 for use with its model 353 universal microscope lamp. It controls the voltage going to the lamp's bulb.
There is a metal housing resting on 4 rubber feet. It has a black crackle finish in enamel. The front has a rotating knob with an index, but no adjacent scale. Voltage is read off a Triplett AC voltmeter (model 233) fixed into the top of the housing. Its scale runs 0-10 volts. The rear of the housing has a power cord and a socket for the lamp's cord. The socket is brown plastic and reads "AERIAL GROUND."
There is a metal housing resting on 4 rubber feet. It has a black crackle finish in enamel. The front has a rotating knob with an index, but no adjacent scale. Voltage is read off a Triplett AC voltmeter (model 233) fixed into the top of the housing. Its scale runs 0-10 volts. The rear of the housing has a power cord and a socket for the lamp's cord. The socket is brown plastic and reads "AERIAL GROUND."
Signedon plaque on side of housing: TRANSFORMER / MODEL 393 / 11-18 VOLT AMPS. 60 CYCLE / VOLTS PRI. 117 VOLTS SEC. 6.5 / SPENCER LENS CO. / BUFFALO, N. Y., U. S. A.
on meter face: TRIPLETT / MODEL NO. 233 / TRIPLETT ELEC. INST. CO. BLUFFTON, OHIO, U. S. A.
on meter face: TRIPLETT / MODEL NO. 233 / TRIPLETT ELEC. INST. CO. BLUFFTON, OHIO, U. S. A.
Historical AttributesUsed by William A. Jackson, first librarian of Houghton Library, and William H. Bond, another Houghton librarian. A note dated 1954 and signed by Bond accompanied spare parts for the transformer (which were not accessioned).
When Houghton Library opened in 1942, Jackson invested in a lot of state-of-the-art equipment for examining books and investigating them. The apparatus included microscopes, black lights, and special lamps. This was one of them.
When Houghton Library opened in 1942, Jackson invested in a lot of state-of-the-art equipment for examining books and investigating them. The apparatus included microscopes, black lights, and special lamps. This was one of them.
Primary SourcesSpencer Lens Company, Spencer Stereoscopic Microscopes (Buffalo, NY: Spencer Lens Company, [1940?]), 17.
ProvenanceWilliam A. Jackson, Librarian, Houghton Library, Harvard University, c. 1942 ; transfer to CHSI courtesy of Dennis Marnon, 2009.