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
- GUID (Link to Original Record)
- http://n2t.net/ark:/65665/ng49ca746a5-1c93-704b-e053-15f76fa0b4fa
