Ramsden Dividing Engine

Object Details

Jesse Ramsden

Description

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.

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.

Location

Currently not on view

Credit Line

Gift of Henry Morton

1775

ID Number

MA.215518

catalog number

215518

accession number

40282

Object Name

dividing engine

Physical Description

bronze (overall material)

brass (overall material)

mahogany (stand material)

Measurements

overall: 109 cm x 123 cm x 114 cm; 42 29/32 in x 48 7/16 in x 44 7/8 in

overall: 58 in x 60 in x 60 in; 147.32 cm x 152.4 cm x 152.4 cm

place made

United Kingdom: England, London

See more items in

Medicine and Science: Mathematics

Time and Navigation

Measuring & Mapping

National Museum of American History

subject

Mathematics

Ruling and Dividing Engines

Revolutionary War

Record ID

nmah_694508

Metadata Usage (text)

CC0

GUID (Link to Original Record)

http://n2t.net/ark:/65665/ng49ca746a5-1c93-704b-e053-15f76fa0b4fa