274 
BATHYMETRICAL SURVEY OF 
map is 1001 Heet above the" sea, though the date is not mentioned. The 
temperature of the surface water was 49°*5 Fahr. 
Loch Dochard (see Plate CXXVII.) lies about 3 miles to the west of Loch 
Tulla, into which it drains. There are some huge boulders on the shore, 
and the river both on entering and leaving the loch has considerable 
volume, silting up having taken place at the inflow, while at the outflow 
rock is exposed on both sides. The loch is somewhat irregular in outline, 
trending east and west, and is about two-thirds of a mile in length. The 
superficial area is about 86 acres, and tbe drainage area nearly 8 square 
miles. The maximum depth of 42 feet was recorded near the centre of the 
wide part of the loch. The volume of water is estimated at 44 million 
cubic feet, and the mean depth at 12 feet. The loch was surveyed on May 
18, 1903, but the level could not be ascertained, though it was estimated 
from spot-levels to be about 735 feet above the sea. The loch is fairly 
simple in conformation, the deep water occupying a central position, but a 
sounding in 15 feet was taken towards the northern shore, surrounded 
by depths exceeding 25 feet. A spit of sand and boulders projects into the 
loch from the southern shore, and from its extremity a shoal or causeway, 
covered by 2 or 3 feet of water, extends to the western shore ; in close 
proximity to this shoal soundings in 17 and 18 feet were recorded. 
The surface temperature over the deej) part of the loch was 48°'0 Fahr., 
whereas in the shallow bay at the east end the temperature of the surface 
water was no less than 6° higher, viz. 54°*0. 
Loch Tulla (see Plate CXXYIII.) lies about 8 miles north-west of Tyn- 
drum, and only 2 miles to the south of Lochan na h-Achlaise, in the Tay 
basin. It trends in a north-east and south-west direction, and is 2J miles 
in length, and nearly a mile in maximum breadth, the mean breadth being 
nearly half a mile. The superficial area is about 703 acres, or over a 
square mile, and the drainage area about 57 square miles, including Loch 
Dochard. The maximum depth of 84 feet was recorded in two places near 
the centre of the loch, about a quarter of a mile to the north-east of the 
central island. The volume of water is estimated at 1167 millions of cubic 
feet, and the mean depth at 38 feet. The loch was surveyed on April 16, 
1903, the elevation above the sea being determined by levelling from bench- 
mark as 542*3 feet. According to the hotel-keeper, the water was low at 
the time, the range in level being about 6 feet. 
The loch is complex in conformation, due largely to the presence of a 
small island (Eilean an Stalcair) near the middle of the loch, opposite the 
exit of the river Orchy, in the vicinity of which the bottom is irregular, 
and the contour -lines sinuous in character. The main body of water lies 
to the north-east of the island, where there is a 50 -feet basin nearly 1^ 
miles in length, enclosing a 75-feet basin over three-quarters of a mile in 
length. To the south-west of the island there is a small subsidiary 50 -feet 
