Robert Falcon Scott (1868-1912)
An oxidised and brass marching compass, mica cover, with prismatic sight, two shades and folding wire-sight, [circa 1902], 4in. (11cm.) long, in fitted calf leather case.
Provenance: Robert Falcon Scott (1868-1912, early ink inscription on the cover of the leather case "Capt. 'Discovery' 1902"); by descent.
One of the variety of scientific instruments carried by the southern party in their instrument box, Scott found difficulties with compasses in the trying conditions of the Antarctic. Readings could be variable: 'I took a round of bearings with the prismatic compass, and then asked Barne to do the same; he got different readings, and on trying again myself, I got a third result. The observations only differed by a few degrees, but it shows that these compasses are not to be relied upon where the directive force is so small...After this I depended for all bearings on the compass attached to our small theodolite, which possessed a simple light needle and seemed to give greater accuracy. I record this fact, because it was important that we should obtain accurate observations on our extended sledge journeys, and it would be well that this point should be more carefully considered in future expeditions.' (R.F. Scott, The Voyage of the "Discovery", London, 1907 new edition, II, pp.16-17); and in the low visibility of a blizzard, the compass lost out to the direction of snow drifting against Shackleton's back: 'After this we tried steering by compass; Shackleton and Wilson pushed on before the wind, whilst I rested the compass in the snow, and when the needle had steadied directed them by shouting; then as they were disappearing in the gloom, I had to pick up the compass and fly after them...At length I made up my mind that we could only hope to hold an approximate course, and getting Shackleton well ahead of me, I observed the manner in which the snow was drifitng against his back, and for the remainder of the day I directed him according to this rough guide.' (op.cit., p.70).