MARCH £4, 1907] 
MATE: 
mile, and a mean breadth of half a mile, covering an area 
of 1540 acr 
; the maximum depth is 436 feet, 
=s, and containing 13,907 million cubic feet of 
water and the mean 
Photo. | Fic. 2.—Loch Lochy, from the southern end. 
depth 207 feet. The loch forms a narrow triangle, broadest 
towards the south and tapering towards the outflow, the 
steep slope of the hills being continued under water. The 
basin is simple, all the contours approximately following 
the shore-line, but the line of greatest depth is nearer the 
western shore. The 4oo-feet area is about two miles in 
length, the two ends approaching very close to the west 
side, where the steepest slopes occur. The valley is so 
narrow relatively to the depth of the loch that, in the 
central parts, the steep slopes reach far towards the middle 
and leave comparatively little level bottom, but towards 
the south end, where the loch is broader and not quite so 
deep, there is a greater extent of nearly flat bottom. It 
is interesting to note that seiches were first observed by 
the staff of the Lake Survey in Loch Tre 
g. 
Loch Ossian lies at an elevation of about 1270 feet 
above the sea to the north of Rannoch Moor, trending 
north-east and- south-west, with its long axis slightly 
curved, and of nearly uniform breadth throughout. It is 
3% miles long, and nearly half a mile in greatest breadth, 
the mean breadth being one-third of a mile. The super- 
ficial area is nearly 660 acres, and the volume of water 
about 1224 million cubic feet, the maximum depth 132 
feet, and the mean depth 43 feet. The lake-floor is very 
uneven, both the transverse and longitudinal sections being 
undulate. 
Loch Laggan, situated between the Highland and West 
Highland Railways, the coach road from Kingussie to 
Tulloch passing along the northern shore, trends north- 
east and south-west, and is of the usual elongate, narrow 
form of Scottish lochs, narrowest in the central parts and 
somewhat expanded towards each end, where deeper water 
cecurs; the outline is very irregular, and the bottom 
correspondingly irregular, with a number of larger and 
smaller islands in the narrower parts. It is more than 
seven miles in length, two-thirds of a mile in maximum 
breadth, the mean breadth being nearly half a mile, and 
the superficial area about 1900 acres. The maximum depth 
is 174 feet, the mean depth 68 feet, and the volume of 
water about 5600 million cubic feet. The shallower con- 
tour lines are continuous, and follow approximately the 
outline of the shore, but all the deeper contours are much 
broken up. There are four 75-feet areas und six 100-feet 
areas, the largest and deepest approaching the west end. 
Lochan na h-Earba is the name applied to two distinct 
lochs (now differing by nearly ro feet in level, though 
they may once have formed a single loch) lying in a valley 
NO. 1950, VOL. 75] 
running nearly parallel to, and about a mile to the south 
of, that occupied by Loch Laggan. The west locn 1s the 
larger and deeper of the two, nearly two miles long by 
one-third of a mile in greatest 
breadth, covering an area of about 
263 acres, and containing 408 million 
cubic feet of water, with a maxi- 
mum depth of 81 feet and a mean 
depth of 353 feet. The basin is 
simple, the contour lines being con- 
tinuous, but narrowing more de- 
cidedly than the outline from the 
centre to each end, the slopes being 
much steeper towards the centre of 
the loch. The east loch is about 
half a mile distant from the west 
loch, the stream conveying the over- 
flow from the west loch winding 
through the boggy flat between 
them. It is 1; miles long by a 
quarter of a mile in greatest breadth, 
covering an area of about 146 acres, 
and containing 191 million cubic 
feet of water, with a maximum 
depth of 69 feet and a mean depth 
of 31 feet. The water is all 
towards the upper end, the lower 
half being very shallow. 
the larger lochs thus 
briefly summarised, details are given 
in the paper of Loch Pattack, the 
highest loch surveyed in the basin, 
with a maximum depth of 58 feet 
deep 
Besides 
V/ames Chumiley. 
and a mean depth of 14 1ee; 
of Loch Ghuilbinn, with a maximum depth of 49 
feet and a mean depth of 13 feet; of an Dubh Lochan, 
a very small but relatively deep loch near Loch Treig, 
Photo. James ( Ye 
Fic. 3.—Loch Arkaig, from the east end. 
with a maximum depth of 40 feet and a mean depth 
of 15% feet; of Lochan Linn da-Bhra, with a maxi- 
mum depth of 25 feet and a mean depth of 8} feet; and 
