and their reptile predecessors by analysis of the embryo. Cherry-Garrard suffered from a high degree of myopia, seeing little without the spectacles that he could not wear while sledging. In almost total darkness, and with temperatures ranging from , they man-hauled their sledge from Scott's base at Cape Evans to the far side of Ross Island. The party had two sledges, but the poor surface of the ice due to the extremely low temperatures meant that they could not drag both sledges as intended during parts of the outward journey. They were thus forced to relay, moving one sledge a certain distance before returning for the other. This highly inefficient means of travelling – walking for every one advanced – meant at times they could only travel a couple of miles each day. Frozen and exhausted, they reached their destination in 19 days and built an improvised rock wall igloo with canvas roof on the slopes of Mount Terror just a few miles from the penguin colony at Cape Crozier. They managed to collect three penguin eggs intact before a force eleven blizzard struck on 22 July, ripping their tent away and carrying it off in the wind. The igloo roof lasted one more day before it too was ripped away by the wind, leaving the men in their sleeping bags under a thickening drift of snow, singing songs and hymns above the sounds of the storm to keep their spirits up. When the winds subsided on 24 July, by great fortune they found their tent lodged in a hollow drift at the bottom of a steep slope half a mile away. Cherry-Garrard suffered such cold that he shattered most of his teeth due to chattering in the frigid temperatures. Desperately exhausted by the cold and lack of sleep, they left anything they didn't need behind and began their return journey. Only progressing a mile and a half some days, they eventually arrived back at Cape Evans shortly before midnight on 1 August. Cherry-Garrard later referred to this as the 'worst journey in the world' at the suggestion of his neighbour George Bernard Shaw, and gave this title to his book recounting the fate of the 1910–1913 expedition. Polar journey On 1 November 1911, Cherry-Garrard set off to accompany the team that would make the attempt on the South Pole, along with three supporting parties of men, dogs and horses.