"Sledging", a watercolour by Wilson, date unknown. This was later published in Scott's Last Expedition. 
"The worst surface we have struck, very heavy pulling," wrote Scott, "but we came 6 1/2 miles (geo.). It will be a strain to keep up distances if we get surfaces like this. We seem to be steadily but slowly rising. The satisfactory thing is that the second party now keeps up, as the faults have been discovered; they were due partly to the rigid loading of the sledge and partly to the bad pacing." 
"The marches are terribly monotonous," he added. "One's thoughts wander occasionally to pleasanter scenes and places, but the necessity to keep the course, or some hitch in the surface, quickly brings them back. There have been some hours of very steady plodding to-day; these are the best part of the business, they mean forgetfulness and advance." 
The terrain on the descent was a mixture of sastrugi and blue ice. "We went with the speed of lightning," wrote Amundsen. He and the other skiers "had a hard job to keep up with the sledges. The drivers support themselves on their sledges, are pulled along on skis, and have halcyon days." 
The skiing, wrote Bjaaland, was "as easy as it could possibly be [but] had my work cut out to keep ahead of Helmer's dogs. Just as I thought they were well behind, I found them sticking their noses in front, just next to me." 
Wisting rigged a sail on his sledge.
 "Pictures From the Terra Nova Expedition : Watercolours by Dr. E. A. Wilson" at Cool Antarctica.
 R.F. Scott, diary, 29 December, 1911, quoted by Roland Huntford in Race for the South Pole : the expedition diaries of Scott and Amundsen (London : Continuum, c2010), p.212-213. This part of the entry does not appear in the online version of Scott's journals at Project Gutenberg. It seems to have been conflated with the entry for 30th December, possibly an error and not a deliberate omission, as it appears in print editions such as that by Methuen.
 R.F. Scott, diary, 29 December, 1911, quoted in Scott's Last Expedition, v.1.
 Roald Amundsen, diary, 30 December, 1911, quoted by Roland Huntford in Scott and Amundsen (New York : Putnam, 1980, c1979), p.498.
 Olav Bjaaland, diary, 30 December, 1911, quoted by Roland Huntford in Scott and Amundsen (New York : Putnam, 1980, c1979), p.498.