108 



DR HUGH ROBERT MILL ON THE 



and two maximum negative slopes in November, the third in December. But in August 

 1886 the positive slope was only 0° - 6, and the curve below 2 fathoms (No. 4) was 

 practically homothermic. This was probably an accidental result, due to temporary 

 mixture by winds. 



There were two well-marked types of curve at this station, one paraboloid or 

 approaching the hyperbola, the other S-shaped, and at opposite seasons both curves 



Table XLI. — Temperature Observations at Shandon. 



No. . . . 



Date . . . 

 No. of Points 

 Temp. . . . 

 Slope . . . 



1 



13.4.86 



3 



41-4 

 + 1-9 



2 



21.4.86 



7 



42-0 

 + 1-2 



3 



16.6.86 

 6 



47-6 

 + 1-8 



4 

 3.8.86 



7 



52-9 

 + 0-6 



5 



24.9.86 



4 



54-4 

 + 0-7 



11.11.86 

 6 



50-5 

 -1-7 



28.12.86 

 6 



44-4 

 -2-4 



8 



9 



10 



2.2.87 



25.3.87 



6.5.87 



6 



6 



6 



43-1 



42-9 



45-7 



-1-0 



-o-i 



+ 1-6 



11 



13.6.87 

 9 

 50-4 



+ 2-8 



No. . . . 



Date 



No. of Points 



Temp. . . . 



Slope . . . 



12 



6.8.87 



9 



57-4 

 + 3-2 



13 



30.9.87 



4 



54-1 

 -0-2 



14 



29.11.87 

 6 



46-8 

 -1-7 



15 



9.2.88 

 6 



43-8 

 -0-3 



16 

 28.3.88 

 3 

 42-0 



17 

 7.6.88 

 6 

 46-5 



-0-1 i +1-3 



18 



20.8.88 



3 



52-8 

 + 3-6 



19 



6.9.88 



6 



53-6 

 + 2-0 



20 

 22.10.88 



6 



49-9 

 -0-3 



21 



25.10.88 



6 



50-0 

 -0-1 



showed reversed slopes. These forms were only hinted at in the Eow II. observations. 

 Representative examples are given in fig. 46, Plate XXXI. Nos. 7 and 10 were the two 

 best marked hyperbolas. No. 7 (December 1886) was a cooling curve of high negative 

 slope ; it indicated the existence of 5 fathoms of surface water (from 41° surface to 44°'l), 

 showing a rapid rise of temperature with depth, separated by an intermediate layer 

 from 10 fathoms of almost uniform temperature (44° - 9 to 45° - l). No. 10 is a 

 warming curve (May 1887), showing high positive slope. The change here is 

 remarkably abrupt. From the bottom at 20 fathoms to 5 fathoms the temperature 

 rises only from 45°"2 to 45°*3, showing that three-quarters of the mass is homothermic. 

 From the depth of 3 fathoms, with temperature 45° - 6, the water heats rapidly to 49°'3 

 on the surface. In this case three observations — surface, 5 fathoms, and bottom — would 

 have sufficed to determine the true character of the temperature distribution, but if the 

 three observations had been at any intermediate position, they would have been mis- 

 leading. 



The S-shaped curve was shown fairly well in the central stations of the Clynder 

 observations. It indicates a stratified or heterothermic arrangement of layers of water 

 at different temperatures. The best examples shown at Shandon were Nos. 6 (negative) 

 find 3, 11, and 12 (positive). Here many and close observations are required to define 

 the various inflections, and No. 11 is the best. The typical S-curve shows the following 



