THE FRESH-WATR LOCHS OF SCOTLAND. 



89 



about half a mile from the southern end, based on soundings in 82 and 

 83 feet. Within the largest 75-feet basin, and about 1J miles from 

 the northern end, is the 100-feet basin, about half a mile in length, 

 enclosing the maximum depth of the loch. The areas between the contour- 

 lines at intervals of 50 feet, and the percentages to the total area, are 

 as follows : 



Feet. Acres. Per cent. 



Oto 50 571 ... 52-3 



50 100 485 ... 44-6 



Over 100 34 ... 3-1 



1090 100-0 



Loch Eck was surveyed on June 20-22, 1903, when the elevation was 

 found to be 66'6 feet above the sea, which agrees closely with the elevation 

 determined by the Ordnance Survey officers on June 9, 1863, viz. 06*8 feet. 

 Temperature Observations. Two serial temperatures were taken on 

 June 22, 1903, one at 2.30 p.m., in the deepest part of the loch, in 135 feet 

 of water, and the other at noon, about a quarter of a mile to the south, 

 in 74 feet of water, with the following results : 



The series in the deepest basin shows a range from surface to bottom 

 of 13*5, the greatest fall being one of 4 between 20 and 27 J feet. The 

 shallower series shows a range of W'-l in the 70 feet of water, the greatest 

 fall being one of 4 3 -8 between 35 and 42^ feet The " sprungschicht " 

 was thus observed nearer the surface in the deepest basin, the temperature 

 at a depth of 35 feet being 4'3 lower than at the same depth in the 

 shallower water to the south, while at 50 feet the temperature was 

 practically the same in both series. A strong south-east wind was blowing 

 at the time these observations were taken, which might explain the higher 

 readings at the surface and at 20 feet in the more northerly position. 



From the following table it will be seen that in the three lochs under 

 consideration 372 soundings were taken, and that the aggregate area of the 

 water-surface is just over 2 square miles, so that the average number of 

 soundings per square mile of surface is 180. The aggregate volume of 

 water contained in the lochs is estimated at 2525 millions of cubic feet. 

 The area drained by these lochs is nearly 43 square miles, or 21 times 

 the area of the lochs. 



