2012-03-052012-03-05About 19202012-03-05http://hdl.handle.net/2152.3/489There is an earlier Spencer instrument in the collection (1.051), with similar features to the above, which may date from about 1920. Signed: Spencer Microscope ALOE Co. Sales Agents No 61515.en-USAmerican FirmsBiologyMicroscopyOpticsImage