While we were still laughing over the flight of the Arab on coming in contact with civilisation in the guise of a small electric machine, two Englishmen appeared in view, riding horses, and guarded by a considerable number of Indian troopers and a few of the Aden corps, and followed by a large train of baggage-animals. I had been told before leaving Aden that I might meet a surveying-party under Captains Domville and Wahab, who had been told off by the Indian Government to organise a survey of the tribe-lands lying between the Turkish frontier and Aden. Although they had been successful up to this point, they began here to meet with difficulties on the part of the natives, which at length, after I had passed on into Turkish Yemen, became so demonstrative that guns were once or twice resorted to by the natives, and the scheme had to be abandoned before it was completely carried out. I spent the afternoon with them, and very pleasant it was. I was able also to obtain from them the correction of my aneroid barometer, for so far I had not resorted to boiling-point tubes, keeping what few instruments I had with me as much as possible in the dark, so as to excite as little suspicion as possible. After dinner in the luxurious camp of Captains Wahab and Domville, I sauntered back to find my men already preparing to load the camels, and soon after midnight we made a start. It was a bright, clear, moonlight night, but chill and cold, a sure sign that we were ascending to the highlands, which an altitude of nearly two thousand feet on my barometer showed to be the case. The Arabs shivered and chattered as we pushed along through the valley. Presently the road ascended on the left side of the stream, and we crossed a plateau at an elevation of a few hundred feet above the river. The cold as dawn appeared became almost intense, and I was glad to alight from my camel and run races with my men, getting often a long way ahead of the caravan. Then we would sit down and light a little fire of mimosa-twigs, over which we would huddle together to keep warm until the camels caught us up again. [Illustration: _A Valley in Yemen_.]