[aboard the ‘James Caird’ along on the way to South Georgia]
–from Frank Worsley’s account ‘Endurance’—
“On the thirteenth day we were getting nearer to our destination. If we made the tragic mistake of passing it we could never retrace our way on account o the winds and currents, it therefore became essential that I should get observations. But the morning was foggy, and if you cannot see the horizon it is impossible to measure the altitude of the sun to establish your position. Now the nearer your eye is to the surface of the sea, the nearer is the horizon. So I adopted the expedient of kneeling on the stones in the bottom of the boat, and by this means succeeded in taking a rough observation.
“It would have been a bold assumption to say that it was a correct one, but it was the best that I could do. Two observations are necessary, however, to fix your position, and my troubles were far from over; for a noon, when I wanted to observe for latitude, I found conditions equally difficult. The fog, which before had been on a level with us and was hovering between the sun and ourselves, so that all I could see was a dim blur. I measured to the centre of this ten times, using the mean of these observations as the sun’s altitude.”