THE FRESH- WATER LOCHS OF SCOTLAND. 123 



Loch is irregular in outline, and the conformation of the bottom is also 

 irregular, shallow water extending out into the loch in some places, 

 while in other places comparatively deep water approaches close to the 

 shore. The maximum depth of 17 feet was observed near the southern 

 end of the loch, and a sounding of 15 feet was taken near the centre of 

 the wide portion of the loch, in close proximity to a sounding of 5 feet. 

 The diversity in the soundings gives a sinuous character to the 10-feet 

 contour-line. The area of the lake-floor covered by less than 10 feet of 

 water is about 22 acres, or 62 per cent, of the total area of the loch. 

 The loch was surveyed on July 3, 1903, but the elevation above the sea 

 could not be determined. The water rises about 2 feet above, and 

 falls about 1 foot below, the level on the date of the survey ; there is a 

 sluice at the outflow, but it was out of order and disused at the time of 

 the survey. Temperatures taken at 10 a.m. in the position of the 

 deepest sounding gave 58'0 at the surface and 57'5 at a depth of 

 16 feet. 



Loch of Lintrathen (see Plate XXXIII.). The Loch of Lintrathen, 

 from which Dundee draws its water-supply, has been raised in level to 

 the extent of 22 feet in connection therewith; the water in the loch 

 was 14 inches below the overflow on the date of the survey, so that the 

 20-feet contour-line would show approximately the size and position of 

 the original loch. It receives the drainage from a large tract of the 

 hilly country to the north, and it flows by the Melgam water into the 

 river Isla. It is surrounded by gently sloping cultivated ground or 

 woods, with gravelly margin, except in the north-western angle of the 

 loch, where the Melgam water and Inzion burn enter, which is shallow 

 and obstructed by weeds. It is nearly 1J miles in length from south- 

 west to north-east, with a maximum breadth of three-quarters of a 

 mile, the mean breadth being nearly half a mile, or 33 per cent, of the 

 length. Its waters cover an area of nearly 400 acres, or considerably 

 more than half a square mile, and it drains an area 47 times greater, 

 or nearly 29 square miles. Nearly 120 soundings were taken, the 

 maximum depth observed being 70 feet. The volume of water con- 

 tained in the loch is estimated at 405,207,000 cubic feet, and the 

 mean depth at 23 J feet, or 34 per cent, of the maximum depth. The 

 length of the loch is 104 times the maximum depth, and 311 times the 

 mean depth. The Loch of Lintrathen forms a simple basin, the bottom 

 sloping down, with few irregularities, to the deepest part, which is 

 situated in the wide south-western portion of the loch. The maximum 

 depth of 70 feet was observed to the north of Loch Craigs, considerably 

 nearer the southern than the northern shore, and the slope of the 

 bottom off Loch Craigs is evidently very steep, a sounding of 26 feet 

 having been taken close to the shore. The line of soundings taken 

 northwards from Loch Craigs shows a slight rise of the bottom towards 



