On the 30th the weather suddenly changed. In any other region a storm and torrents of rain might have been expected: angry-looking clouds covered the sky, and lightning, unaccompanied by thunder, gleamed through the mass of vapour. But condensation did not ensue--not a drop of rain fell on to the thirsty soil. The sky remained overcast for some days, and the fog rendered the points of sight invisible at the distance of a mile. The astronomers, however, would not lose time, and determined to set up lighted signals and work at night. The bushman prudently advised caution, lest the electric lights should attract the wild beasts too closely to their quarters; and in fact, during the night, the yelp of the jackal and the hoarse laugh of the hyena, like that of a drunken negro, could plainly be heard. In the midst of this clamour, in which the roar of a lion could sometimes be distinguished, the astronomers felt rather distracted, and the measurements were taken at least less rapidly, if not less accurately. To take zenith distances while gleaming eyes might be gazing at them through the darkness, required imperturbable composure and the utmost _sang-froid_. But these qualities were not wanting in the members of the Commission, and after a few days they regained their presence of mind, and worked away in the midst of the beasts as calmly as if they were in their own observatories. Armed hunters attended them at every station, and no inconsiderable number of hyenas fell by their balls. Sir John thought this way of surveying delightful, and whilst his eye was at his telescope his hand was on his gun, and more than once he made a shot in the interval between two observations. Nothing occurred to check the steady progress of the survey, so that the astronomers hoped before the end of June to measure a second degree of the meridian. On the 17th they found that their path was crossed by an affluent of the Kuruman. The Europeans could easily take their instruments across in their india-rubber canoe; but Mokoum would have to take the caravan to a ford which he remembered some miles below. The river was about half-a-mile wide, and its rapid current, broken here and there by rocks and stems of trees embedded in the mud, offered considerable danger to any light craft. Matthew Strux did not fail to represent this, but finding that his companions did not recoil from the attempt he gave way. Nicholas Palander alone was to accompany the caravan in its _détour_. He was too much absorbed in his calculations to give any thought to danger; but his presence was not indispensable to his companions, and the boat would only hold a limited number of passengers. Accordingly, he gave up his place to an Englishman of the crew of the "Queen and Czar," who would be more useful under the circumstances.