94 BATHYMETRICAL SURVEY OF 



Temperatures taken in the deepest part showed a range of less than 

 2 Fahr. : 



Surface 58-2 Fahr. 



10 feet 58-2 



20 '. 58-0 



25 ... 57'7 



30 57-0 



40 56-3 



Loch Muck (see Plate XXXVI.). A small loch, shaped like the 

 letter L, lying about a mile east of Loch Doon, with which it is connected 

 by the Muck burn, entering the head of the bay called the Ford of Moak. 

 It is barely half a mile long and one-fifth of a mile broad at the southern 

 end. There is a slight constriction in the middle, where the depth is 

 only 7 feet. North of this is a slight depression, with a depth of 10 feet ; 

 to the south is a deeper basin, with the maximum depth of 22 feet. The 

 mean depth is 7 feet, the area about 28 acres, and the volume 9 millions of 

 cubic feet. The area drained is about 1J square miles. The Polnaskie 

 burn enters just "where the Muck burn flows out southwards. The surface 

 was 992-4 feet above the sea on July 20, 1903. 



Temperatures in the deepest part gave 



Surface 58-2 Fahr. 



5 feet 57-4 



10 56-4 



20 56-3 



Bogton Loch (see Plate XXXVI.). This is simply a shallow, weedy 

 expansion of the river Doon, 2 miles north-west of the outflow from Loch 

 Doon. It is two-thirds of a mile long, a quarter of a mile broad, and 

 4 feet in greatest depth. The bottom is flat, and nearly everywhere covered 

 by 3 feet of water. The mean depth is 2 feet, the area 60 acres, and the 

 volume 5 millions of cubic feet. The area drained, including Loch Doon, 

 etc., amounts to 60 square miles. The surface was 522*6 feet above sea- 

 level on July 13, 1903, or more than 150 feet lower than Loch Doon, 

 showing the very rapid fall in the intervening 2 miles. 



The surface temperature at the north-west end was 56' 6 Fahr., at the 

 south end 57-5. 



Martnaham Loch (see Plate XXXVI.). A narrow loch, lying 5 miles 

 south-east of the town of Ayr. The shores are partly wooded, partly 

 smooth fields. Nearly midway between the ends the ruins of Martnaham 

 Castle stand on an island, connected with the south shore by a causeway. 

 The shores of the western basin are fringed with reeds. The axis of the 

 loch runs north-east to south-west. The length is 1 miles, and the 

 greatest breadth, in the middle of the loch, where a deep bay runs to 

 the north-west, is a quarter of a mile. 



There are three small basins, the western one being the deepest, with 



