On Commander John Ross’s 1818 voyage to search for the North-West Passage,

To justify the expedition’s scientific aims the Admiralty and the Royal Society donated chronometers and compasses – the Isabella carried seven different models of each – plus a number of other instruments, among them Henry Kater’s Pendulum for measuring the ellipticity of the globe, Mr Plentty’s Cork Life Boat, Englefield’s Mountain Barometer and Companion, Burt’s Buoy and Knipper, Trengrouse’s Apparatus for Saving Lives, and Troughton’s Whirling Horizon. John Ross would later contribute to the array with a dredging device of his own invention which he whimsically christened ‘the Deep Sea Clamm’.

Fergus Fleming, Barrow’s Boys (1998)