Ramsden Dividing Engine
date: label: date made
content: 1775
name: label: maker
content: Jesse Ramsden
notes: label: Description
content: Making precisely divided scales was of great importance to eighteenth and nineteenth century navigation and science. In 1775 the English instrument-maker Jesse Ramsden completed this machine, designed to divide arcs of circles automatically. The instrument has a mahogany frame with three legs and three frictionless wheels. These wheels support a heavy bronze wheel which is covered on its outer rim with a brass ring, cut with 2160 gear teeth. These teeth engage a screw on one side of the machine. Turning this screw 6 times rotates the carriage for the stylus exactly one degree. An object to be divided was clamped to the arms of the bronze wheel, with the cutting mechanism was above it.
label: Description
content: Ramsden's invention won him an award from the British Board of Longitude. By the mid-nineteenth century, even small American instrument-makers had begun to buy dividing engines. The Philadelphia firm of Knox and Shain, which made navigational instruments, purchased Ramsden's dividing engine from his successors for their use.
label: Location
content: Currently not on view
place: label: place made
content: United Kingdom: England, London
topic: label: Subject
content: Mathematics
label: Subject
content: Ruling and Dividing Engines
label: Subject
content: Revolutionary War
setName: label: See more items in
content: Medicine and Science: Mathematics
label: See more items in
content: Time and Navigation
label: See more items in
content: Measuring & Mapping
creditLine: label: Credit Line
content: Gift of Henry Morton
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.215518
label: catalog number
content: 215518
label: accession number
content: 40282
objectType: label: Object Name
content: dividing engine
physicalDescription: label: Physical Description
content: bronze (overall material)
label: Physical Description
content: brass (overall material)
label: Physical Description
content: mahogany (stand material)
label: Measurements
content: overall: 109 cm x 123 cm x 114 cm; 42 29/32 in x 48 7/16 in x 44 7/8 in
label: Measurements
content: overall: 58 in x 60 in x 60 in; 147.32 cm x 152.4 cm x 152.4 cm