150 
BATHYMETRICAL SURVEY OF 
extends from about a quarter of a mile from the east end to E-udh’ an 
Alt-toir, and is 4| miles in length. The four areas exceeding 200 feet 
in depth, proceeding from east to west, are — (1) a large eastern basin 
IJ miles in length, extending from south-east of Ardvreck Castle to 
north of Garbh Dhoire ; (2) a small basin lying 150 yards to the west 
of the first-mentioned, based on a sounding of 210 feet; (3) a large 
western basin 1| miles in length, extending from south of the eastern 
islands off the north shore to north of Torr a’ Chail; and (4) a small 
basin less than 100 yards further west, based on a sounding of 214 feet. 
The three 250-feet basins are all very narrow, one enclosed in the large 
eastern 200-feet basin, J-mile in length and with a maximum depth of 
264 feet, the other two enclosed in the large western 200-feet basin, the 
smaller having a maximum depth of 270 feet, the larger being nearly a 
mile in length and including the maximum depth of the loch (282 feet), 
which occurs to the north of Eilean Assynt. It will be observed that 
the deep channel does not coincide with the central axis of the loch, but 
lies for the greater part of its course much nearer the southern than the 
northern shore ; opposite Ardvreck Castle, however, it crosses over and 
lies nearer the northern shore in the eastern end of the loch. The 
numerous large bays along both shores were found to be fairly deep. 
The areas of the lake-floor at different depths, and the percentages 
to the total area of the loch, are as follows : — 
0 to 
50 feet, 
572 acres 
29 per cent. 
50 ,, 
100 „ 
559 ,, 
28 
J 9 
100 „ 
150 ,, 
351 ,, 
18 
5 5 
150 „ 
200 „ 
270 „ 
14 
5 » 
200 „ 
250 ,, 
]84 „ 
9 
3 3 
Over 
250 ,, 
46 „ 
2 
3 3 
1982 ,, 
100 
3 3 
More than half the entire lake-floor is covered by less than 100 feet 
of water, and the areas on both sides of the 50-feet contour-line are 
nearly equal, indicating a moderate and uniform average slope down 
to the depth of 100 feet, beyond which depth the slope becomes much 
steeper. 
Loch Assynt was surveyed on September 12 to 18, 1902. On the 
12th the elevation of the lake-surface above the sea was determined, 
by levelling from bench-mark, as being 215T feet; subsequently heavy 
rains set in, so that on the 16th the water had risen to the extent of a 
foot, and on the 18th to the extent of 16 inches, above the level on the 
12th, and the later soundings were corrected in order to bring them 
into agreement with the earlier ones. When levelled by the officers of 
the Ordnance Survey on September 9, 1871, the surface of the water 
