Mechanical log

This instrument is designed to measure the distance covered by a ship. In this design, a brass rotor trails in the water and spins around as the boat moves along. This rotary motion is then passed through a register. Three dials marked '1/4-1', '1-10' and '10-100' give a readout of the distance travelled in nautical miles. The dials are also protected while the log is in the water by a brass swivelling cover. This form of log was patented by Edward Massey (about 1768-1852), whose name is inscribed on the converter, along with the trademark of three Ls in a triangle.

Object Details

ID: NAV0728
Collection: Astronomical and navigational instruments
Type: Mechanical log
Display location: Display - ROG
Creator: Massey, Edward
Date made: circa 1830
Exhibition: Ships, Clocks & Stars: The Quest for Longitude
Credit: National Maritime Museum, Greenwich, London
Measurements: Overall: 110 mm x 335 mm x 500 mm

Your Request

If an item is shown as “offsite”, please allow eight days for your order to be processed. For further information, please contact Archive staff:

Tel: (during Library opening hours)

Click “Continue” below to continue processing your order with the Library team.