Everything in camp that could be cleaned in water was washed in the lake during the day, and the ground near our tents looked like an improvised laundry. It was strewn in all directions with articles spread out to dry. Those boys who had no change of garments, stayed in the water while their clothes were aired in the sunshine, and enjoyed it. Both Christians and Mussulmans received an ox on this day in order that they might make biltong for the journey. We bought flour and grain and sheep and fowls, and laid in as large a stock of provisions as we could carry for use in the uninhabited borderland between Delgi and Gallabat. February 12 was our last day beside Lake Tsana, and the prospect of leaving it filled me with regret. The “Sultan” came into camp again, and in answer to one or two questions gave us the following information: that the rainfall on the margin of the lake in the wet season is not great; the heavy rains descend upon the heights around, and the floods are carried down the rivers and khors in overwhelming torrents, so that all the watercourses are then impassable. This circumstance, of course, has a very important bearing on the possibility of a commercial development of the region. Before quitting the subject, I will bring to the reader’s notice Dr. Stecker’s thoughtful conclusions as to the present relation of the River Abai to Lake Tsana:— “I made another extremely interesting discovery in the Gorgora mountains, viz. of a remarkable shell, which by its character reminds one of the oyster.[103] We found both the shells and the living creatures in abundance on the shore. With lemon juice they taste like genuine oysters. But it is remarkable that I had already found this species in the Blue Nile, and that I found it later on the island of Dek, enclosed in unmistakable volcanic rock (tuff). I can only offer this explanation, that, at a time when Lake Tsana already existed, a great eruption took place in the south. According to my view the lake had its origin in tertiary times as a consequence of a great volcanic movement in the north (at the Gorgora range). The Abai, which was previously an unimportant stream, and described the great curve which is indicated on my map by arrows, and now carries it round Dek and Dega, was forced in consequence to the south-western and southern shores, though its original course can still be traced quite distinctly. The second volcanic movement took place, according to my opinion, in the south, and the islands of Dek[104] and Dega in Lake Tsana owe their origin to it, as do a whole series of islands beside the eastern shore of the lake and the masses of rock of volcanic origin which encumber the course of the Blue Nile and lie scattered in the whole valley of that river.”[105]