THE FRESH- WATER LOCHS OF SCOTLAND. 115 



of over one-third of a square mile. Nearly 40 soundings were taken, 

 the maximum depth observed being 46 feet. The volume of water is 

 estimated at 29,271,000 cubic feet, and the mean depth at 19 feet, or 

 42 per cent, of the maximum depth. The length of the loch is 40 times 

 the maximum depth and 100 times the mean depth. Loch Hoil 

 consists of a main body, which trends almost north and south, sending 

 out an arm in an easterly direction leading to the outflow. This arm 

 is shallow, while the body of the loch is comparatively deep; at the 

 junction of the arm and body is a heap of stones about 200 feet from 

 the eastern shore. The body of the loch forms a simple basin, the 

 bottom sloping down on all sides towards the deepest part, which is 

 approximately centrally placed, but rather nearer the northern than 

 the southern end. The average slope of the bottom is gentle, the 

 steepest gradient observed being one of 1 in 4-6 off the southern shore, 

 where a sounding of 13 feet was taken 60 feet from the shore. The area 

 of the lake-floor covered by less than 20 feet of water is about 24 acres, 

 or 68 per cent, of the total area of the loch; that covered by water 

 between 20 and 40 feet in depth is about 9 acres, or 26 per cent. ; and 

 that covered by more than 40 feet of water is about 2 acres, or 6 per 

 cent. The loch was surveyed on May 28, 1903, and, from spot-levels 

 near the loch, it was calculated that the surface of the water was about 

 1600 feet above the sea. 



Temperature Observations. Temperatures taken in the deepest part 

 of the loch gave the following results : 



Surface 57'0 Fahr. 



10 feet ... 52-0 



20 48-0 



40 47'0 



This series shows a range of 10 from surface to bottom, there being 

 a fall of 5 between the surface and 10 feet, and a further fall of 4 

 between 10 and 20 feet. 



Loch Fender (see Plate XXXI.). Loch Fender lies to the north of 

 Loch Freuchie, and flows by the Glenfender burn into the river Bran. 

 It contains large trout, but the fishing, which is preserved, is uncertain, 

 sometimes yielding splendid sport, at other times none at all. It was 

 surveyed on the same day as Loch Freuchie by means of a boat kindly 

 supplied by Mr. Bulloch of Kinloch. The Marquis of Breadalbane 

 sounded Loch Fender about 40 years ago from a portable boat, and 

 found a maximum depth of about 30 yards ( = 90 feet) ; the maximum 

 depth recorded by the Lake Survey was 78 feet. Loch Fender is thus 

 extremely interesting on account of its great depth, considering its 

 small dimensions. The shores are rocky all round, and the southern 

 shore is a steep slope of bare rock, rising gradually to Creag an Loch ; 



