Clapp-Eastham high potential condenser
Date: circa 1915
Inventory Number: 0335a,b
Classification: Condenser
Subject:
Maker: Clapp-Eastham Company (1906 - 1929)
User: Cruft Laboratory, Harvard University (founded 1914)
Cultural Region:
Place of Origin:
Dimensions:
30.2 x 25 x 16.5 cm (11 7/8 x 9 13/16 x 6 1/2 in.)
Bibliography:
Radio Telegraph Apparatus. Catalog S
Description:
This condenser is made of glass plates, coated with foil on both sides. The two sections of plates are assembled from 16 of these glass plates, each section separated by a wooden slab. The two sections are mounted in a wooden rack on which brass terminals are attached. They are connected in parallel. This object is called a standard unit, and its capacity is 0.1 mF (0.1 milli farad). The original price in 1915 was $8.
In Collection(s)
Signedon instrument: Clapp Eastham Co. / Cambridge, Mass. U.S.A.
FunctionA condenser acts merely as a storage tank for the energy derived from a transformer, which is rapidly filled and emptied as sparks occur at the spark gap. As the trade catalogue mentions, "You would not consider storing valuable liquids in a leaky vessel or one which slopped over, and yet this is exactly what occurs with most types of condenser. The most evident signs of leakage are heating and (if the condenser is transparent) brushing or spraying at the edges." Although it could have different uses, this condenser was advertised as a component of radio telegraphy.