Besidts of Some Experiments upon the Bate of Evaporation. 63 



sometimes lower than that touching the yellow, the differences being 

 considerable. One whole series gave the red invariably lower, the 

 mean defect being 1-3°. 



The evaporation results for the first ten weeks are (A) : — 



Colour. 



Mean Temperature 

 at XVII. 



Total Evaporation. 



Purple 



Blue 



Green 



o 



59-14 

 59-08 

 5900 

 59-08 

 59-06 

 58-32 

 64-88 



Inches. 

 7-695 

 7-335 

 7-115 



Yellow 



Eed 



Tank 



7-265 

 7-690 



Air 









And for the second ten weeks (B) :- 



Colour. 



Mean 



Temperature 



at XIV. 



Mean 



Temperature- 



at XVII. 



Mean 



Temperature 



XIV. and XVII. 



Total 

 Evaporation. 



Purple 



Blue 



Green 



Yellow 



Eed 



Tank 



Air 



76-08 

 75-22 

 7408 

 74-80 

 75-54 

 71-52 

 81-54 







7008 

 70-18 

 69-72 

 69-64 

 69-82 

 69-56 

 79-50 



o 



7308 

 72-70 

 71-90 

 72-22 

 72-68 

 70-54 

 80-52 



Inches. 

 12-955 



12-880 

 12-480 

 12-530 



12-885 



It is curious that in each of these ten-week periods the gauges 

 stand in the same order with regard to the water evaporated, i.e., 

 beginning with that losing the least : — 



Nos. II., IV., v., III., I. 



The mean of the noted temperatures at XVI I. is not, however, in 

 the same order ; the first rising sequence being : — 



and the second : — 



Nos. III., L, II., v., IV., 



I., III., II., v., IV. 



which is, notwithstanding, a remarkably similar pair. But both the 

 evaporation and temperature arrays are doubtless accidental, 

 although it is not unlikely that the former may be contributed to l)y 

 some small differences in the sizes of the gauges, more particularly 



