Name/Title
Pump, VacuumEntry/Object ID
1993.040.0003Description
Vacuum Pump; used in Benicia High School Science Class when the school was located at 250 East L Street; the teacher was Mr. Ira Guthrie.
Vacuum Pump with Bell Jar
Maker: Chicago Apparatus Company, Chicago, Illinois
Trade name: Milvay Scientific Instruments
Date: ca. 1925–1940; probably 1930s
Materials: Cast iron, steel, brass/bronze, glass, rubber/composition
Function: Physics laboratory and classroom demonstration apparatus
Description:
Hand-operated laboratory vacuum pump and glass bell jar manufactured by the Chicago Apparatus Company of Chicago, Illinois, under its Milvay Scientific Instruments trade name. The apparatus consists of a heavy black-painted cast-iron base supporting a single-cylinder piston vacuum pump operated by a large flywheel and articulated hand lever. A removable clear glass bell jar with integral knob rests on a circular gasketed vacuum plate connected to the pump.
Operation of the pump removes air from beneath the bell jar, producing a partial vacuum for experiments and classroom demonstrations involving atmospheric pressure, expansion of gases, boiling under reduced pressure, transmission of sound, and related principles of physics.
A metal manufacturer's plate attached to the base bears the Milvay name and identifies the Chicago Apparatus Company. The company was established in Chicago in 1908 and by 1920 marketed Milvay laboratory apparatus specifically for educational use. Comparable Chicago Apparatus scientific equipment appears in the company's 1920s and 1930s physics catalogs.
has two parts: a metal unit and a glass bellCollection
Benicia School Collection
