108 Proceedings of Boy al Society of Edinburgh. [sess. 
western shore near the south-western end, forming a big delta 
which is extending into the loch. The delta is wooded in contrast 
with the other shores, which are but scantily clothed with vegeta- 
tion. The Black Burn flows into the loch near the middle of the 
south-eastern shore, and does not form a delta, for it runs down 
a steep rocky slope. 
We found the deepest part of the loch where the mountain slopes 
on the opposite sides are steepest and the valley narrowest , this fact 
being an important one, as will be shown further on. Our 
soundings (87) show that the basin is of simple conformation, the 
bottom sloping on all sides towards the deepest part. Indeed the 
bottom of Loch Muick is a very flat one, as shown by the follow- 
ing figures : — 
Feet. 
Acres. 
Per cent. 
0 to 50 
170-41 
31-06 
50 „ 100 
95-96 
17-49 
100 „ 150 
68-59 
12-51 
150 „ 200 
90-63 
16-52 
200 „ 250 
113-37 
20-67 
over 250 
9-60 
1-75 
548-56 
10000 
The contour lines of depth approach each other more closely along- 
the south-eastern shore , showing that the slope is steeper there than 
along the opposite shore. 
The valley or glen in which Loch Muick lies has been occupied 
in the Great Ice Age by a glacier, as is shown by its U-shaped 
cross-section. That shape is the most appropriate one for the 
glacier’s movements, according to Penck,* the well-known con- 
tinental authority in glacial matters. 
Loch Muick partakes both of the character of a rock basin and 
of a barrier basin. The barrier is the latest moraine thrown down 
by the glacier that once crept along the glen, and it serves still, as 
at first, to dam back the drainage. A small part of the barrier is 
above the level of the water, but by far the greater part is sub- 
* Dr A. Penck, “Glacial Features on the Surface of the Alps,” Geogr* 
Teacher, vol. iii. , p. 49, 1905. 
