254 BATHYMETEICAL SURVEY OF 



interesting results, for from the surface down to 45 feet the temperature was 

 found to be practically uniform, but between 45 and 47 J feet a fall of 

 about 5 Fahr. was recorded equal to 2 per foot of depth the total 

 range from surface to bottom being 6-2. The readings were as follows : 



Surface 58-5 Fahr. 



30 feet 58-5 



40 58-0 



45 58-0 



47* ... -. 53-l 



50 52-3 



Linliihgow Loch (see Plate CXIII.) lies close to the town of Linlithgow, 

 with the ruins of the historic palace standing on its southern shore. It 

 is nearly a mile in length from north-east to south-west, with a maximum 

 breadth of a quarter of a mile, the superficial area being about 103 acres. 

 The promontory on which the palace stands cuts the loch into two halves, 

 the north-eastern half being flat-bottomed and shallow (maximum 10 feet), 

 the south-western half deepening from the outflow towards the central 

 promontory, off which the maximum depth of 29 feet was recorded. The 

 volume of water is estimated at 34 million cubic feet, and the mean depth 

 at 7J feet. When surveyed on June 25, 1903, the surface was 149'8 feet 

 above the sea, practically identical with the elevation (149-9 feet) recorded 

 by the Ordnance Survey on May 6, 1896. The following temperatures 

 taken in the deepest part show a range from surface to bottom of 7 Fahr., 

 the greatest fall being one of 3 between 10 and 15 feet : 



Surface 62-2 Fahr. 



5 feet 61-2 



10 58-8 



15 55-8 



25 55-2 



Gartmorn Dam (see Plate CX1V.) lies less than 2 miles from the 

 town of Alloa on the northern shore of the Firth of Forth, and is used in 

 connection with the water-supply to that town. It exceeds a mile in length 

 from east to west, with a maximum breadth of one-third of a mile, the 

 superficial area being about 140 acres, and the drainage area nearly 3 square 

 miles. The water deepens gradually on proceeding from the east end 

 towards the outflow at the west end, where the maximum depth of 21 feet 

 was recorded ; nearly half the bottom is covered by less than 10 feet of 

 water, while nearly 10 per cent, is covered by more than 20 feet of water. 

 The volume is estimated at 65 million cubic feet, and the mean depth at 

 lOf feet. When surveyed on May 17, 1905, the elevation could not be 

 determined from bench-mark, but the scale at the weir showed 17 feet of 

 water. The following temperatures taken in the deepest part show a range 

 of 4 Fahr. from surface to bottom, there being a fall of no less than 3 

 between the surface and a depth of 5 feet : 



