´óÏó´«Ã½

Shan Macdonald, Curatorial assistant for Scientific Instruments selected this object from the Hunterian Museum's collection. Shan writes - This tide gauge was invented by William Thomson (Lord Kelvin) c.1880 and manufactured by his instrument maker James White of Glasgow in 1882.
The gauge was one of several made for the Clyde Docks. It recorded the level of water in the estuary of the River Clyde. The mechanism consists of a fourteen day pendulum clock that drove a chart drum on which was drawn a pencil record of the height of water in the dock.
This measurement was achieved by means of a copper float in a protective tube connected to a stylus via a mechanism that scaled down the vertical float movement from 1ft to 1 cm over a tidal range of c.21ft.