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 delris 
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 
