THE FRESH- WATER LOCHS OF SCOTLAND. 125 



entire lake-floor about 42 per cent, is covered by less than 10 feet of water, 

 and about 8 per cent, by more than 20 feet of water, so that one-half is 

 covered by water between 10 and 20 feet in depth. The temperature of 

 the water was practically uniform throughout, the surface reading being 

 48 0< Fahr., while a reading at 34 feet gave 47'2. 



Milton Loch (see Plate XLIII.). Milton Loch lies less than a mile to 

 the east of Auchenreoch Loch, and about 8 miles from Dumfries. It is 

 irregular in outline and conformation, the general trend being from north to 

 south, but the southern portion curves round Milton point towards the east. 

 The loch exceeds a mile in length, with a maximum breadth of half a mile. 

 The superficial area is about 153 acres, or nearly a quarter of a square 

 mile, and the drainage area is nearly 2 square miles. The maximum depth 

 of 15 feet was recorded both in the northern and southern parts of the loch, 

 there being two 10-feet areas separated by shallower water at the central 

 narrows, the greatest depth between Green island and the opposite shore 

 being 9 feet. The volume of water is estimated at 45 million cubic feet, 

 and the mean depth at nearly 7 feet. Of the entire lake-floor about 78 per 

 cent, is covered by less than 10 feet of water. The loch was surveyed on 

 May 3, 1905, when the elevation was 410*0 feet above the sea, or rather 

 higher than that determined by the Ordnance Survey on December 5, 1893, 

 viz. 409-6 feet. The temperature of the water was uniform throughout, 

 identical readings of 47'0 Fahr. being taken at the surface and at 15 feet. 



Loch Arthur (see Plate XLIII.). Loch Arthur (or Lotus Loch) is 

 situated about 4 miles to the east of Milton Loch, and drains into the Kirk- 

 gunzeon lane at Killywhan Bridge. It is surrounded by cultivated stony 

 fields, with a strip of wood nearly all round and a plantation on the north- 

 east ; the shores are stony, with granite boulders. The loch is two-thirds 

 of a mile in length from east to west, with a maximum breadth across the 

 middle of nearly one-third of a mile, the superficial area being about 

 74 acres. The basin is simple, the contour-lines coinciding with the out- 

 line of the loch, and fairly deep. The maximum depth of 50 feet was 

 observed towards the south-eastern angle, but there is a considerable area 

 approximately in the centre of the loch, equal to one-fourth of the total 

 area, in which the depth exceeds 40 feet. The mean depth is estimated at 

 nearly 26 feet, or over one-half of the maximum depth, and the volume of 

 water at 83 million cubic feet. The loch was surveyed on May 4, 1905, 

 when the elevation was 239*8 feet above the sea, as compared with 240'1 

 feet determined by the Ordnance Survey on January 23, 1894. The 

 temperature of the water was practically uniform throughout, a reading at 

 the surface giving 47 C '2 Fahr., and at 45 feet 46'9. 



