156 



DR HUGH ROBERT MILT, ON THE 



But for the range of density which has to be considered, the value of Do- is practically a 

 constant = 0"96 (range approximately from 0-959 to 0-961), and for the divisions under 

 consideration, taking the volume of the Gareloch at half-tide as a convenient unit, we 

 have the following values of VIV, where V is in every case the volume at half-tide, 

 expressed in units of the capacity of the Gareloch.* 



Gareloch VDa- 



= 0-96 = 



1 



Loch Goil „ 



142 = 



1-48 



Loch Fyne „ 



= 18-52 = 



19-29 



Arran Basin „ 



= 663-77 = 



69143 



Table LXVI. gives the mean temperature of the mass of water in four divisions 

 at the spring minima and autumn maxima, change of temperature, and the quantity 

 of heat gained or lost, which is obtained by multiplying the change of temperature 

 by the foregoing factors. The heat unit employed is the Gareloch-degree, or the 

 amount of heat necessary to raise a mass of pure water equal to the half-tide contents of 

 the Gareloch, from 32° to 33° F. Multiplying by 166,000,000 would give the value 

 in ton-degrees, or multiplying by 371,840,000,000 would give it in Fahrenheit heat 

 units. 



Table LXVI. — Total Heat Changes in the Water of the Clyde Sea Area. 



Division. 



Min. 

 1886. 



Max. 

 1886. 



Change. 



Heat 

 gained. 



Min. 

 1887. 



Change. 



Heat 

 lost. 



Max. 



1887. 



Change. 



Heat 

 gained. 



Min. 



1888. 



Change. 



1 

 Heat 

 lost. 



Gareloch . . 

 Loch Goil 

 Loch Fyne . 

 Arran Basin , 



41°8 

 41-8 

 42-0 



42-0 



54-1 

 49-8 

 49-9 

 51-6 



12°3 



8-0 

 7-9 



9-6 



G. L. 



Units. 

 12-30 



11-84 



IS2-39 



6637-73 



42-7 

 43-7 

 44-3 

 43-6 



ll°-4 

 6-1 

 5-6 

 8-0 



G. L. 



Units. 

 11-40 



9-03 

 108-02 



5531-44 



57-9 

 56-1 

 51-4 

 52-2 



15-2 



12-4 



7-1 



8-6 



G. L. 



Units. 

 15-20 



18-35 



136-96 



5946-30 



41-9 

 43-3 

 44-4 

 42-5 



16°0 



12-8 



7-0 



9-7 



G. L. 



Units. 

 1 6 -oo 



18-94 



135-03 

 6606-87 



It thus appears that Loch Goil, on account of its greater volume, has about the same 

 thermal power as the Gareloch, although its range of temperature is very much less. 

 Loch Fyne has about ten times the thermal power, and the Arran Basin 500 times the 

 thermal power of the Gareloch. Taking the average of heat gained and lost in the two 

 years into account, along with the area of each of the divisions considered, we sec in 

 Tabic LXVIL the actual thermal power per square mile, or the amount of heat stored or 

 returned through each unit of area. 



Taking roughly 5 '5 Gareloch-degree units per square mile as the normal amount of 

 heat exchange between successive maxima and minima, would give for the whole Area a 

 total of 6403*8 units ; but estimating 6 units as a more probable value for the 

 transference per square mile, we would get 6985, or nearly 7000 units. Table LXVII. 



* See Part I., Trans. Boy. Soc. Eilin. 



