EXPLANATION OF TABLE (B). 



An asterisk affixed to any number indicates that it is derived from less than 

 twelve months of observations, in no case, however, are annual amounts given for 

 which more than three months had to be found by interpolation, which was effected 

 either by using the observed amount at the nearest station during the time required, 

 or by using the means from adjacent years for the same month or months. The 

 first mode of interpolation is quite reliable, and was always preferred to the second. 

 Blanks for any one year indicate either no observations or an insufficiency (that is, 

 less than nine months) of record during the year. The annual means at the bot- 

 tom of each column are taken from the preceding table (A), whenever the series 

 was not continuous. 



(87) 



