70 



DR HUGH ROBERT MILL ON THE 



Seasonal Range of Temperature in the Arran Basin. — The mean temperature 

 curves for seasonal change at each of the Arran Basin stations were drawn on a large 

 scale, and combined with a view of getting the true mean annual movement of tempera- 

 ture for the whole mass of the deeper water. The curves for Largybeg, Brodick, and 

 Garroch Head were drawn on one sheet, time being abscissae, and temperature ordinates. 

 A mean curve was drawn freehand through the points determined, mainly the very 

 numerous points of the Garroch Head curve. This gave an approximation to the 

 mean annual conditions of the East Arran Basin, so far as regards the mass of the 

 deep water, the curve embracing two maxima and three minima. 



The curves for Inchmarnoch, off Loch Ranza and Carradale, made a second though 

 less complete set, the mean drawn through which followed most closely the Carradale 

 points, and this may be taken as typical of the West Arran Basin. 



Finally, the curves for Skate Island, Kilfinan, and Otter I. were combined graphically 

 on a third sheet, and represented the conditions of the Central Arran Basin. The 

 three mean curves were then traced off on the same piece of tracing paper, with different 

 coloured inks, and a mean, drawn by eye through the three, was taken as representing 

 the seasonal change of temperature of the mass of the deep water of the Arran Basin as 

 a whole. 



Table XXIII. — Monthly Mean Temperature of Mass of Water in the three 

 Divisions of the Arran Basin from Curve. 



1886. 



Station. 



Jan. 



Feb. 



Mar. 



April. 



May. 



June. 



July. 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 



Arran B. East 









42-2 



44-0 



46-0 



48-4 



50-6 



51-9 



51-5 



49-6 



46-1 



„ West 









42-4 



43-8 



45-6 



48-2 



50-1 



51-2 



51-2 



49-7 



47-1 



,, Central 









42-3 



43-4 



44-8 



47-2 



49-3 



50-6 



51-0 



49-8 



47-4 



„ Mean 









42-3 



43-5 



45-3 



47-7 



49-9 



51-3 



51-4 



49-7 



46-7 













1887. 















Arran B. East 



43-9 



43-5 



43-4 



44-3 



46-2 



48-4 



50-9 



53-0 



53-0 



51-4 



48-4 



45-9 



„ West 



44-4 



43-5 



43-6 



44-8 



47-0 



49-6 



50-9 



52-0 



52-0 



50-7 



48-7 



46-5 



„ Central 



44-9 



44-1 



43-8 



44-2 



45-6 



47-4 



48-7 



50-4 



50-8 



49-6 



48-5 



46-7 



„ Mean 



44-5 



43-7 



43-5 



44-4 



46-2 



18£ 



48-4 

 8. 



50-2 



52-0 



52-1 



50-4 



48-5 



46-3 



Arran B. East 



44-6 



43-2 



42-0 



42-8 



















„ West 



44-6 



42-8 



42-3 



42-8 



















,, Central 



45-4 



44-0 



42-6 



42-8 



















„ Mean 



44-8 



43-4 



42-3 



42-8 



















