Walker’s A1 “Harpoon” Patent Scheepslog Nr. 3380, 1862
Thomas Walker, Birmingham
Maker:
Collectie:
NavigArte
From the 19th century onwards, attempts were made to automate speed measurement using mechanical logs. The aft vanes rotated, and the distance travelled could be read from the dial. Patented in 1861.
From the 17th century onwards people had made many attempts to devise a mechanical log which would automatically record the ships distance done. Edward Massey invented a mechanical log in 1802 with four blades which was used by the Admiralty from 1807-1815. As the rotator was dragged behind the ship then the log rotated and the revolutions were transformed in miles on the dials, to be read after the rotator was brought on deck. The design of Massey was further refined by Thomas Walker and Son, including the stabilizer. Walker took out a patent for the A1 Harpoon Log in 1861.
The earley serial number 3380 suggest manufacturing around 1862 – 1863.