It took Mr. Chanler nine days, starting from a point opposite our Rendili camp, to reach the sycamore tree under which we had slept—or rather tried to sleep—the night before, while the same distance only occupied us five days, which is easily explained by the fact that we had already a general idea of the course of the Waso Nyiro, while Mr. Chanler had to feel every mile of his way. We were now a march beyond the sycamore tree, which formed the limit of his journey, and our men had been some miles farther still down the river and had not seen the swamp. The only hypothesis I can advance which will account for our failure to find Lorian at the place where Mr. Chanler saw it on January 7th, 1893, is this. In very wet seasons, or after a series of wet seasons, the Waso Nyiro overflows its banks and covers a portion of the Kirrimar Plain, forming a vast swamp, or more probably a chain of swamps, to which the name of Lorian has been given by the natives. That the portion of the Kirrimar Plain immediately adjoining the river is at times under water, is beyond a doubt, as I have already mentioned in the previous chapter. After a long drought, by which the supply of water brought down by the Waso Nyiro would be materially curtailed, these swamps dry up, those lying up-stream, owing to their higher level, naturally drying up first, and consequently the western edge of the swamp, or swamps, called Lorian, would gradually recede more and more to the eastward as the drought increased. At the time of our visit in September, 1900, there had been no rain in Samburuland for three years, according to the Rendili, and it is therefore quite reasonable to suppose that Lorian, for the reasons enumerated, had receded many miles to the eastward of the point at which Mr. Chanler turned back, having satisfied himself that Lorian was merely a swamp and not a lake as he had supposed. It is quite possible that the swamp seen by Mr. Chanler may not have been Lorian at all, but may have been only one of the chain of swamps to the west of it and higher up the river, and which had dried up prior to our visit. The evaporation in that terribly hot climate (scarcely one degree north of the Equator, and not more than 700 feet above sea-level) must be enormous, and would be sufficient to dry up even a large lake providing it was not well fed with water, as in the case of Lorian. A shallow body of water with a very large surface-area, such as this swamp, would be very easily dried up in one season if its river-borne water-supply was much reduced.