TRANSACTIONS OF SECTION A. 565 



that at two for at least ten years. The ten stations with a twenty years' record 

 are liondon, England (Camden Square); Port Louis, Mauritius; Calcutta and 

 Bombay, India; Colombo, Ceylon; Adelaide and Melbourne, Australia; Welling- 

 ton, New Zealand ; and Toronto and Winnipeg, Canada ; the two with a ten years 

 record are Malta and Kingston, Jamaica. 



In a series of tables are given the mean monthly nnd annual rainfall and 

 number of days on whicli at least O'Ol inch of rain fell at these twelve stations, 

 and also the maximum and minimum monthly and annual rainfall and number ot 

 days of rain. A summary of these twelve tables is then given. The means in 

 this table are those of the ten stations with records for twenty years, but the 

 extremes are those for the whole of the twelve stations. This table is followed by 

 a summary of the yearly rainfall at the twelve stations. 



It must not be "inferred that the rainfall at the places selected represents the 

 mean rainfall of the countries in which they are .situated. These places are in 

 most cases the principal towns in those countries. Nor are the extremes of the 

 rainfall in the British Empire represented. But it is believed that no previous 

 attempt has been made to ascertain the mean rainfall at nearly so many as ten 

 widely distributed places in the British Empire for nearly so long a period as twenty 

 consecutive and concurrent years. The observations, moreover, have been taken 

 in an entirely uniform manner, and are believed to be thoroughly trustworthy, the 

 results being strictly comparable one with another. 



A few observations are then made on the rain.''all at the various places, and 

 finally a summary of the principal results is given. 



Throughout the British Empire, so far as appears from these observations, the 

 mean rainfall is least in February and greatest in July, increasing every month 

 from February to July, and decreasing every month from July to February. There 

 may be no rain at some one or more of these rainfall stations in any month in the 

 year up to six months in succession. The heaviest fall in any month was 47'64 

 inches at Bombay, in July 1878, and only here has there been rain on every day 

 in any month. In Malta, in 1895, the rainfall was only 11-38 inches; at Colombo, 

 in 1878, it was 139'70 inches. In Malta, in 1888, there were only 59 days of 

 rain ; in Mauritius, in 1893, there were 241 wet days. 



If the twenty years be divided into four periods of five years each it will be 

 found that the mean annual rainfall at the ten stations baa been as follows :^In 

 the first period 47-15 iiiches on 150 days; in the second period 44'67 inches on 

 147 days; in the third period 44-21 inches on 155 days; in the fourth period 

 44-15 inches on 151 days. This does not show much deviation except in the first 

 period (1877-81). This was an exceptionally wet period in England, and now 

 appears to have been generally wet. The mean annual rainfall for the first ten 

 years was 45-92 inches on 149 days, and for the last ten years 44-67 inches on 153 

 days. For the whole period it was 45-29 inches on 151 days. 



In this account of the rainfall at a few meteorological stations in the British 

 Empire, the effects of the seasons have been altogether neglected. Six of the 

 stations with records for twenty years are north of the equator and four are south 

 of it, not a very great inequality. In England the wettest period is nearly the 

 same as in New Zealand, but it happens to be in the summer and autumn in 

 England when in New Zealand it is winter and spring. And taking each place 

 individually there seems to be very little correspondence between the rainfall and 

 the season. It does not appear to be the succession of the seasons which causes 

 the rainfall to increase generally each month from February to July and to 

 decrease each month from July to February, although the very heavy rainfall at 

 Bombay in June and July tells much in making those months appear to be so wet 

 on the average throughout the Empire. 



With a larger number of stations any such disturbing influence as this would 

 be neutralised, and it may be worthy of consideration whether it might not be 

 well to appoint a small Committee of the British Association to collect and digest 

 statistics of the rainfall from a large number of places in the British Empire. 



