70 Mr. W. Marriott on Rainfall. 
and lower, because a high wind drives the rain over the higher 
station. 
The average rainfall for the South-east of England, as recorded 
at Greenwich for the past eighty years, is just under 25 inches. 
As will be seen from the following figures, there have been 
during the past twelve years only two in which the rainfall has 
been above the average, viz. :— 
In. In. In. 
1890—3:06 1894+ 1:92 1898—6'11 
1891+ :006 1895—5:24 1899—2:63 
1892—2'61 1896—2°49 1900—2°64 
18938—4:87 1897—2°88 1901—4:65 
There is thus a deficiency on the twelve years amounting in the 
aggregate to 85°22 inches, which is equal to about a year and a 
half's rainfall. 
The average rainfall varies, of course, in different parts, and 
at Seathwaite in Cumberland is about 140 inches. ‘There the 
. spring months, April, May, and June, are the driest months on 
the average, the fall gradually increasing until January, and then 
again decreasing; whereas in the London area it is found that 
October is the wettest month, July next, and March the driest. 
It has been found useless to base calculations on records of short 
periods, owing to the great variability of the rainfall. Thus, if 
an average were struck from the records of the past ten or twelve 
years in the London district, it will be found to be much below 
the 25 inches recorded as an average for the past eighty years at 
Greenwich. 
Snow and hail are other forms of rain, about one foot of the 
former being equal, speaking roughly, to one inch of rain. Hail- 
stones are particularly interesting, as showing by their structure 
the varying changes of temperature passed through. Fortu- 
nately we do not get in this country such heavy hailstorms as 
occur in Australia, South Africa, and other places, where corru- 
gated iron of ordinary thickness is riddled, but at times we do 
have them very heavy and destructive, in fact sometimes dan- 
gerous. 
Mr. Marriott exhibited a numerous and interesting series of 
lantern-slides illustrating his address, giving diagrams, tables, 
and maps showing the different temperatures existing in different 
parts of the world, both in winter and summer, indicated by 
lines termed isotherms; the rainfall in different countries, and 
the monsoon areas of the East; also portraits of some well- 
known meteorologists. He hoped that more observers would be 
obtained, and the number of stations increased in the Croydon 
district, as it is necessary to obtain accurate information from 
numerous sources and for riodg,.in order that it may be 
of use. PRES PED 
Ses 
