348 
BATHYMETRICAL SURVEY OF 
Monar. A terrace of gravel surrounds the loch, except on the northern 
shore, where the hill an Carnach rises steeply from the lake-shore. 
There is a large island named Eilean a’ Mhuilinn near the east end, and 
two smaller islands at the mouth of the inflowing river at the west end. 
The loch trends in an east-north-east and west-south-westerly direction, 
and is nearly a mile in length, with a maximum breadth in the centre 
exceeding one-third of a mile, whence it narrows towards the two ends. 
The superficial area is about 100 acres, and the area of land draining 
directly into it is about 37 J square miles, but since it receives the 
overflow from Lochs Monar, an Gead, an Tachdaidh, and Calavie, its 
total drainage area is nearly 88 square miles — an area 550 times greater 
than that of the loch. The maximum depth of 94 feet was observed in 
the wide part of the loch towards the northern shore. The volume of 
water is estimated at 150 million cubic feet, and the mean depth at 
over 34 feet. The loch was surveyed on October 12, 1903, when the 
elevation was determined, by levelling from bench-mark, as being 
4 17' 65 feet above the sea; when visited by the Ordnance Survey officers 
on June 1, 1866, the elevation was found to be 417‘5 feet above sea- 
level. A drift-mark was observed 5 feet above the surface of the 
water on the date of the survey, when the level was about its normal. 
Loch a’ Mhuilinn consists of a deep central basin, with two small 
subsidiary shallow basins at the two ends, as shown in the longitudinal 
section on the map. Towards the west end, immediately to the north 
of the island at the mouth of the inflowing river, a depth of 25 feet was 
recorded, separated from the main basin by a rise of the bottom, on 
which a maximum depth of 12 feet was observed. Towards the east 
end, between Eilean a’ Mhuilinn and the mouth of the outflowing river, 
a depth of 24 feet was recorded, separated from the main basin by a 
depth of 3 feet in the narrows between the island and the northern 
shore. In the main deep basin the contour-lines are continuous and 
the bottom regular, seven soundings in depths exceeding 80 feet having 
been recorded to the west and south-west of Eilean a’ Mhuilinn, two of 
them in depths exceeding 90 feet. The area of the late-floor covered 
by less than 50 feet of water is about 72 acres. 
T emperature* Observations . — The following series of temperatures 
taken in the deepest part of the loch shows that the body of water was 
nearly uniform in temperature on the date of the survey, the extreme 
range observed being less than 1° Fahr. : — 
Surface ... 
10 feet ... 
25 „ ... 
50 „ ... 
90 „ ... 
47° -2 Fahr. 
47° -0 „ 
46° -8 „ 
46°-6 „ 
46° -4 „ 
Loch Bunacharan (see Plate LXXXII.). — Loch Bunacharan (or 
