small electric pump model
Date1850-1890
Inventory Number0136
ClassificationPump model
Subject
Maker
American
?
User
Department of Physics, Harvard University
founded 1884
Cultural Region
Place of Use
Dimensions16 x 21 x 12.5 cm (6 5/16 x 8 1/4 x 4 15/16 in.)
Material
DescriptionA rectangular wooden base with a round wooden foot in each corner. A binding post in two corners. A brass pole slightly off-center. Slotted into a sphere at the top of the pole is a long asymmetrical diamond-shaped bar. A tiny U-shaped piece hangs from each end of the bar; a long rod is threaded into the bottom of each U-shaped piece.
The rod on one side submerges into a glass tube. Around the top rim of the tube is a wide mouth with a spout. The rod terminates in a disc whose diameter is fitted to that of the tube. The bottom of the tube is mounted into a less wide rim component which is propped up. The tube rests in a deep dish that is embedded into the wood.
The rod on the other side is connected to a crank, which turns an axle affixed to two six-armed wheels (each looks like an asterisk). The junction where the crank connects to the axle is held in place by a small sphere at the top of a stout brass pillar. Resting on the base between the two wheels is a coil on a spool.
The rod on one side submerges into a glass tube. Around the top rim of the tube is a wide mouth with a spout. The rod terminates in a disc whose diameter is fitted to that of the tube. The bottom of the tube is mounted into a less wide rim component which is propped up. The tube rests in a deep dish that is embedded into the wood.
The rod on the other side is connected to a crank, which turns an axle affixed to two six-armed wheels (each looks like an asterisk). The junction where the crank connects to the axle is held in place by a small sphere at the top of a stout brass pillar. Resting on the base between the two wheels is a coil on a spool.
Signedunsigned
FunctionThis demonstration apparatus was designed to illustrate a practical use of an electric motor. The electromagnet is used to power the two wheels. Their rotational motion is transformed into a vertical one. The balance beam is thus moving up and down, putting in motion the piston inside the glass cylinder. The piston was designed to pump water up the cylinder. Once there, it goes down the spout and back in the pan below.
ProvenanceFrom the Department of Physics, Harvard University.
Thomas Hall
Date: circa 1890
Accessories: pulley rope
Object number: 1997-1-1423
French
Date: circa 1880
Accessories: protecting case with glass window
Object number: DW0095
English
Date: circa 1820
Accessories: wooden case
brass frame with points
glass arm
handle
broken glass (in package)
Object number: DW0504
English
Date: circa 1800
Accessories: Two insulated charge transfer wands.
Object number: 0014
Benjamin Martin
Date: circa 1766
Accessories: rope cord belt
glass globe
conducting pad
in folder: photographs, page containing description, history, and discussion of design, note from Ebenezer Gay regarding conservation work, excerpt from David Pingree Wheatland and I. Bernard Cohen, A Catalogue of Some Early Scientific Instruments at Harvard University (Cambridge, MA: Harvard University, 1949), woodcut with picture of instrument from B. Martin, Young Gentleman and Lady's Philosophy (1759): 139.
X-ray images of parts of the machine can be found in C1-A7.
Object number: 0013