406 



THIRD REPORT — 1836'. 



5. The first remark which I shall make on these results is, 

 that the diminution of the quantity of ram received at different 

 heights above the ground, as compared with that received on 

 the ground, is very accurately represented by a simple formula 

 involving one constant, viz. the square root of the height of 

 the station above the ground, and one variable coefficient. 



Thus, m V h = the diminution of rain at the given height. 

 In these experiments 



*/ h for the Minster gauge = 

 for the Museum gauge = 



^ 212-833 = 14-5885 



43-666= 6-6080 

 Taking m = 2*29, we have for the whole year. 



Ratios 



For the 



{By calculation 

 By observation 



66-5 

 66-1 



m = 2-88,) 

 . 58 

 . 58-6 

 {m = 1-97,) 



> to 100. 



7 coldest months 

 By calculation . 

 By observation 

 For the 7 warmest months 



By calculation ... 71-3 

 By observation . . 71-2 

 For the 5 coldest months (/« = 3-06,) 

 By calculation . . . 55-4 

 By observation . . 56'2 

 For the 5 warmest months {m = 1'75,) 

 By calculation . . . 74-5 

 By observation . . 73*7 

 In these, which are the longest averages attainable from the 

 experiments, there is an almost exact agreement between 

 the calculated and the observed results, the greatest error 

 being ^-Vth. 



In shorter averages of three months, and, indeed, though 

 less exactly, in every single month when much rain fell, we 

 may recognise the same constant relation. Thus we have 

 For the summer quarter {m = 1'43,) 



84-91 

 85-3 



81 

 80-5 



87-0 

 87-1 



79-8 

 79 



88-4 

 89-2J 



By calculation 



By observation 

 For the winter quarter (?» 



By calculation . 



By observation 

 For the spring quarter {m 



By calculation . 



By observation 



For the autumn quarter {m = 2-19,) 



By calculation 

 By observation 



79-0 



77-1 



= 3-79,) 



. 44-6 



. 49-3 



= 2-84,) 



58-6 



59-8 



90-5 

 92-5 



74-7 

 70-5 



8M 

 80-0 



> to 100. 



68-1 

 65-8 



85-4 

 87-7^ 



