CLYDE SEA AREA. 



83 



water of Loch Fyne may be traced by means of the curves, as at Skate Island. Instead 

 of taking the Inveraray or Strachur observations alone, the two are combined, with the 

 effect of considerably smoothing the curves (see figs. 16 to 18 on Plate VII.). The dates 

 are selected to correspond with those at Skate Island ; the references to the curves are 

 given in Table XXX. The numbers correspond with those for Skate Island (Table XX.). 



Table XXX. — Typical Vertical Temperature Curves in Loch Fyne. 



6 



> 



u 



B 

 O 



1886-87. 



1887-88. 



1888. 



Keference 

 Table 



Date 

 (Mean). 



Time 



Interval 



Days. 



Reference 

 Table 



Date 

 (Mean). 



Time 



Interval 

 Days. 



Reference 

 Table 



Date 

 (Mean). 



Time 



Interval 



Days. 



I 



II 



III 



IV 



V 



VI 



VII 



XXVIII. 



1-2 

 3 



4 

 6 



7 

 8 

 9 



XXIX. 



1 



2 

 3 

 6-7 

 8 

 9 

 10 



April 19 

 June 21 

 Aug. 11 

 Sept. 25 

 Nov. 17 

 Dec. 29 

 Feb. 4 



63 



51 

 45 

 53 

 42 

 37 



XXVIII. 



10 

 11 

 12-13 

 15 

 16 

 18 

 19 



XXIX. 



11 



12 



13-14 



16 



18 

 19 

 20 



March 29 

 May 10 

 June 26 

 Sept. 23 

 Nov. 11 

 Dec. 17 

 Feb. 14 



53 



42 

 47 

 89 

 49 

 36 

 59 



XXVIII. 



21-22 

 23 



25 



26-27 



XXIX. 



21 



22 



23-24 



26 



March 28 

 June 4 

 Aug. 26 



Oct. 17 



42 

 68 

 83 



52 



While the form of the curves is different in detail for each year, there is sufficient 

 similarity between them to suggest that the year 1886-87 may be taken as a type. The 

 only difficulty which this year presents is the low temperature and perfect homother- 

 micity of its minimal curve. If that could be set aside, the difference in range varies in 

 a very interesting way with depth. At the surface the seasonal amplitude may be as 

 much as 20°, at 10 fathoms it is only 10°, at 35 fathoms 5°, and at 70 fathoms only 2°. 

 Plotting these values, and extending the curve to the depth of 105 fathoms, the annual 

 range would come out as only 1°, and at 150 fathoms it would practically vanish. The 

 contrast of this condition with that at Skate Island is striking. There it would appear 

 that the range of seasonal temperature at the bottom is scarcely less than that at the 

 surface, and its value may be taken as at least 10°. The regime of the deep water as 

 regards temperature is thus entirely different in the two basins. The physical 

 differences are that Loch Fyne is smaller, shallower, more completely invested by high 

 land, more completely barred off from the open sea, and with a greater difference 

 between the density of surface and bottom water than is the case in the Arran 

 Basin. The most striking difference in the curves is the absence of homothermic 

 change of temperature in Loch Fyne except in very rare cases. Considering homo- 



