358 
JOUENAL OF THE EOYAL HOKTICULTURAL SOCIETY. 
departures m mean temperature, &c., from the monthly means for 1900 
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, 
1826-1869 (referred to in Vol. xxiii., p. 391) was not available for this 
purpose, as it gives no maxima or minima temperatures. The rainfall 
averages used in diagram 1 are, however, those given by Mr. Glaisher for 
the forty-four years ending 1869 at Chiswick. 
Diagram 1. — This diagram is intended to show at a glance the general 
Fig. 168. 
character of the weather of each month of the year under discussion as 
regards temperature and rainfall. For instance, it will be seen that there 
were only four months — February, March, May, and August — which were 
in any way unseasonably cold, and that July and December were both, on 
the other hand, most exceptionally warm. Then, as regards rainfall, it 
will be noticed that on only four months did the rainfall exceed the 
average, while all the other months of the year were more or less 
unseasonably dry. 
