STATISTICS. 



809 



a certain proportion to the number of the 

 influences which are brought to bear on each 

 unit of each collection of facts. 



It must not, however, be forgotten that the 

 figures in these several tables represent only 

 possible errors. It may happen that the fi>st 

 25 observations brought together may yield 

 an average differing by less than a single unit 



from the mean of thousands of observations ; 

 and there is always a balance of probability 

 in favour of the average even of a small num- 

 ber of facts approximating more closely to 

 the true average than to the extremes. That 

 this is the case will be evident on the most 

 cursory inspection of the following tables, 

 of which the first is founded upon the facts 



