102 Proceedings of the Royal Physical Society. 



steered his rude canoe, and dropt his bronze knife in the stream ; 

 or if you connect together the whole relics found in the same 

 portion of the bed, that of man who had dwelt on the river banks 

 at that early time, when the stream ran over this ancient channel, 

 with cattle, and his dog, in pursuit of which he may have waded in 

 the rough bed of the river. You have next a sudden stop put to 

 the rapid current of the river, at the lower extremity of this valley, 

 probably by an extensive landslip, following long-continued rains, 

 or winter's frost and snow, which might easily have occurred, there, 

 from the right bank on the south, a little farther down the stream, 

 where the steep bank still exposes its broken strata of shales and 

 limestones, all sloping down towards the river bed. The result of 

 this supposed landslip would be the formation in the Kinleith valley 

 of a large still pool or lake, from which the gradual deposit of silt 

 and sand would take place, as it has done to a depth of nearly 

 five feet. The river, however, would at last cut through the 

 barriers by which it had been for some considerable time pent 

 up ; but its course has now been somewhat changed ; for, instead 

 of spreading over the valley, or running, as it may have done, to- 

 wards its southern side, the river now finds its way along the 

 northern margin, partly directed, it may have been, by the 

 freshets of the Kinleith burn bringing down abundance of debris 

 from its deeply-cut bed, which, becoming arranged principally 

 along the right or south bank of the Water of Leith, especially at 

 the upper end of the valley, would assist in forming the present 

 haugh, and turning the stream towards the northern side of the 

 valley, to occupy its present bed. 



Mr Bruce, at my desire, compared the level of the strata exposed 

 at the bottom of this excavation, with that of the same strata in 

 the bed of the stream immediately to the north of his works ; in 

 both places the strata were irregularly broken up in a similar 

 manner, and there seemed not much difference between them, the 

 old bed in the excavation being perhaps about a foot or so above 

 the present bed of the river. Over the old river-course, with its 

 accumulation of gravel, a bed of sand had next been formed, to a 

 depth altogether of 11 or 12 feet, and the river had apparently 

 never again returned to its older bed, the debris over which now 

 forms a continuous bank, sloping down to its present channel, at a 

 distance of 293 feet from this excavation. The absence of any 

 upper or secondary beds of gravel among the sand and silt of 

 the excavation, shows that the river had never returned to this 



