548 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Mean relative humidity of the air at 9 a.m. (complete saturation being 



represented by 100) 88 



Rain fell on 9 days to the total depth of 1*44 in. 



(Equivalent to about 6| gallons on each square yard of surface in the Gardens.) 

 Heaviest fall on any day 0*37 in. on the 10th 



The Diagrams. — The averages with which the different mean monthly 

 temperatures are compared in diagrams 1 and 2 are derived from the 



Diagram 1. — Variation from the Average in Mean Temperature and 

 Rainfall for each Month during the Year 1903. 



1. Average or seasonable Temperature. 2. Average or seasonable Rainfall. 



Fig. 160. 



observations taken at Kew Observatory during the twenty-five years 

 ending 1896. The actual averages for Kew have not been used, but the 

 departures in mean temperature, &c, from the monthly means for 1903 

 at that Observatory have been applied to the Chiswick temperatures ; and 

 in this way very close approximations to the true monthly averages have 

 been obtained. Mr. Glaisher's discussion of the Chiswick temperatures, 



