278 
BATHYMETKICAL SUKVEY OF 
a maximum depth of 29 feet, the other to the north of the island including 
the deepest water in the loch. 
The following temperatures taken in the deepest part show a range of 
6°’9 Fahr., a fall of 4°-8 being recorded between 25 and 45 feet: — 
Surface 56°*0 Fahr. 
25 feet 53°-9 „ 
45 „ 49°-1 „ 
Lochan na GeaJaich (see Plate CXXIII.). — This small loch is situated 
about a mile to the north-west of Loch Awe, into which it drains at Tay- 
chreggan, and is sub-circular in outline, with a maximum diameter of about 
one-fifth of a mile, and covering an area of about Id acres. Two soundings 
were taken at the maximum depth of 25 feet near the middle of the loch. 
The volume is estimated at 7 million cubic feet, and the mean depth at 
10 feet. It was surveyed on May 25, 1903, but the level could not be 
determined. The surface temperature was 59°*0 Fahr. 
Fortsonachan Hill Lochs (see Plate CXXIII.).^ — Four little lochs at an 
elevation of 1300 feet and over on the hill to |^the south of Portsonachan 
were sounded by members of the Lake Survey staff, while engaged on the 
survey of Loch Awe, on May 28, 1903. The most northerly one, called 
Eainbow Loch, has a maximum depth of 26 feet ; the neighbouring one, to 
the south-west, called Loch Choire na Cloich, has a maximum depth of 
20 feet ; the next one, to the south, called Lochan Dhu, has a maximum 
depth of 12 feet ; while the most southerly one, called Lochan Allt na 
Mult, is the smallest and shallowest of the group, not exceeding 3 feet in 
depth. 
Sior Loch (see Plate OXXIX.). — The name Sior Loch is applied to 
three shallow little lochs about IJ miles to the south-west of Loch 
Nant, into which they drain by the Abhainn Cam Linne. They are ra])idly 
becoming bog — very reedy, with the bottom covered by a thick mass of 
vegetation. The middle loch was the only one sounded on June 4, 1903, 
as the boat could not be transported to the other basins ; the maximum 
depth of 4 feet was observed in several places towards the east end. The 
elevation given on the Ordnance Survey map is 733 feet above the sea, 
though the date is not mentioned. 
Loch Nant (see Plate CXXIII.) lies little more than 2 miles north-west 
of Loch Awe at Kilchrenan, but drains northward into Loch Etive. It is 
irregular in outline, trending in a north and south direction, and is nearly 
a mile in length, with a maximum breadth of one-third of a mile. Its 
waters cover an area of about 140 acres, and it drains an area exceeding 
9 square miles, including Sior Loch. The maximum depth of 92 feet was 
recorded in the southern portion of the loch. The volume of water 
is estimated at 148 million cubic feet, and the mean depth at over 24 
