THE FRESH- WATER LOCHS OF SCOTLAND. 85 



Strathtay, lying to the north-east of Loch Kennard and west of Loch 

 Skiach, and flowing by the Balnaguard burn into the river Tay shortly 

 before its junction with the river Tummel, is over a quarter of a mile in 

 length, with a maximum breadth of about one-eighth of a mile, the 

 mean breadth being about one-sixteenth of a mile or 21 per cent, of the 

 length. Its waters cover an area of about 11 J acres, and it drains an 

 area 13 times greater, or about a quarter of a square mile. Twenty- 

 five soundings were taken, the maximum depth observed being 12 feet. 

 The volume of water is estimated at 2,888,000 cubic feet, and the mean 

 depth at nearly 5| feet, or 48 per cent, of the maximum depth. The 

 length of the loch is 123 times the maximum depth, and 258 times 

 the mean depth. The loch forms a simple basin; the deeper water is 

 found towards the southern end, the three soundings exceeding 10 feet 

 being centrally placed in the southern half of the loch. Only three 

 soundings were taken under 5 feet close to the shore, so that the slope 

 of the bottom is on the whole moderately steep. The area of the lake- 

 floor covered by less than 10 feet of water is over 10 acres, or 88 

 per cent, of the total area of the loch, and only a small proportion of this 

 area is covered by less than 5 feet of water. Loch Scoly was surveyed 

 on May 29, 1903. The temperature of the surface water was 63-0 

 Fahr., and a reading at 5 feet gave the same result, while a reading at 

 10 feet gave 56 0> a fall of 7'0 in the temperature of the water at 

 10 feet as compared with that at 5 feet. 



Loch Ordie (see Plate XXVI.). Loch Ordie is a very pretty loch 

 situated amid grouse-moors to the east of the river Tay, and surrounded 

 by wooded hills; it is a good trouting loch, but strictly preserved. It 

 trends in an east-and-west direction, being widest towards the west end 

 and narrowing somewhat towards the east end. It is nearly two-thirds 

 of a mile in length, and nearly half a mile in maximum breadth, the 

 mean breadth being over a quarter of a mile, or 44 per cent, of the 

 length. Its waters cover an area of about 116 acres, or nearly one-fifth 

 of a square mile, and it drains an area nearly 24 times greater over 

 4 square miles. Sixty-five soundings were taken, the maximum depth 

 observed being 69 feet. The volume of water is estimated at 133,110,000 

 cubic feet, and the mean depth at 26J feet, or 38 per cent, of the 

 maximum depth. The length of the loch is 49 times the maximum 

 depth, and 128 times the mean depth. Loch Ordie is extremely simple 

 in conformation, the bottom sinking gradually on all sides down to the 

 greatest depth, which is approximately centrally placed, though rather 

 nearer the west than the east end. The 25-feet basin is about two-fifths 

 of a mile in length and over a quarter of a mile in maximum width, 

 while the 50-feet basin is about a quarter of a mile in length and one- 

 seventh of a mile in maximum width. The area of the lake-floor 

 covered by less than 25 feet of water is about 66 acres, or 57 per cent. 



