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| © National Maritime Museum, London |
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Repro ID: D4690 |
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Description: The cross staff was first described in the 14th century and is thought to derive from a surveying instrument. It was taken up by navigators about a century later and is one of the earliest known Western navigational instruments. By moving one of the sighting vanes along the staff, angular measurements between the horizon and a celestial body can be read off the scale on the staff. Different length vanes are used according to the angle being observed. This relatively simple tool was the principle method of celestial navigation until the back staff came into use in the 17th century. They are usually made of wood allowing them to be made relatively quickly and cheaply. This rare example, however, made by Thomas Tuttell around 1700, is made from highly decorated ivory. It was probably a part of a gentleman's presentation set rather than for use on board ship.As well as being an instrument maker, Tuttell was made Hydrographer to the King in 1700. This appointment was to prove fatal; he was drowned in January 1702 while making a survey of the River Thames. |
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Creator: Thomas Tuttell |
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Date: c. 1700 |
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