<54 



DR HUGH ROBERT MILL ON THE 



fathoms, its deepest point, on August 1st. This failure of the heat to penetrate in 1887 

 is very remarkable, as the water-temperature at the preceding minimum had not been so 

 low as the year before, and the unprecedented heat of June might be expected to have a 

 great effect. The Garroch Head diagram shows no trace of this effect ; and the only hint 

 conveyed is by the tendency of the June 1887 vertical curve to assume the sickle shape. 

 The temperature section for June (No. X., Plate X.) shows a large mass of cold water at the 

 head of the Central Arran Basin, tapering away off Skate Island, and disappearing a little 

 south of Inchmarnoch. By July this had disappeared. The existence of the intermediate 

 layer of cold water, however, shows that the usual vertical movements leading to mixture 

 and equalisation of the temperature in the lower layers had by some means been restricted. 

 The density affords no clue to the cause of this, as the water, both at surface and bottom, 

 was considerably above the average, and the difference between them was very much less 

 than usual. The calmness of the season might be brought forward to explain the effect, 

 but this should have produced an even more marked appearance of the intermediate 

 minimum in Loch Fyne, where none was observed. From the incomplete data for 1888, 

 it seems to have been a year resembling 1887, except that the maximum bottom tempera- 

 ture was even lower. 



Observations off Kiljinan Bay. — The soundings were made in the axis of the Arran 

 Basin, off Kilfinan Bay, Otter House bearing E. 2 miles 2 cables, and the depth 80 

 fathoms. About this position the depths are very irregular, but for 14 miles down the 

 Basin there is never less than 75 fathoms in the centre. The density of the water was 

 only occasionally observed, but we may assume it as intermediate between Skate Island 

 and Otter I. 



The curves resemble those for Skate Island, though somewhat less regular, and it is 

 unnecessary to discuss them farther in thi? place. 



Table XXI. — Temperature Observations off Kiljinan Bay. 



No. . . . 



1 



2 



3 



4 



5 



6 



7 



8 



9 



10 



11 



12 



Date 



29.3.87 



10.5.87 



15.6.87 



7.7.87 



15.8.87 



23.9.87 



16.12.87 



3.1.88 



14.2.88 



22.3.88 



4.6.88 



19.10.88 



No. of Pts. . 



9 



12 



9 



9 



12 



9 



12 



12 



9 



9 



12 



9 



Temp. . . 



43-9 



44-6 



46-6 



47-8 



49-6 



51-7 



48-1 



46-6 



44-8 



43-2 



44-8 



49-9 



Slope . . 



+ 0-2 



+ 2-0 



+ 4-4 



+ 5-8 



+ 5-8 



+ 4-9 



- 2-7 



-0-9 



-1-0 



-0-9 



+ 4-7 



+ 0-1 



H.D.* . . 



75 



55 



35 



20(?) 











35 



25 



65 



60 



30 



75 



h.t. . . . 



43-9 



443 



45-2 



46-3 







48-9 



46-8 



44-9 



43-3 



43-2 



49-9 



Depth assumed as 75. 



Observations at Otter I. — Observations were usually made with Otter Beacon bearing 

 N.E. by E. 7 cables, where the depth was 30 fathoms. This point was just outside 

 Otter Spit, where the tide runs strongly into and out of the Gortans Basin of Loch Fyne. 



