SECT. 3.] Arrangement and Formation of the Series. 25 



part and organ, and so on. Some of the most extensive of 

 these express the heights of 25,000 Federal soldiers from the 

 Army of the Potomac, and the circumferences of the chests 

 of 5738 Scotch militia men taken many years ago. Those 

 who wish to consult a large repertory of such statistics can 

 not be referred to any better sources than to these and other 

 works by the same author 1 . 



Interesting and valuable, however, as are Quetelet s sta 

 tistical investigations (and much of the importance now 

 deservedly attached to such enquiries is, perhaps, owing 

 more to his efforts than to those of any other person), I can 

 not but feel convinced that there is much in what he has 

 written upon the subject which is erroneous and confusing as 

 regards the foundations of the science of Probability, and the 

 philosophical questions which it involves. These errors are 

 not by any means confined to him, but for various reasons 

 they will be better discussed in the form of a criticism of his 

 explicit or implicit expression of them, than in any more in 

 dependent way. 



3. In the first place then, he always, or almost always, 

 assumes that there can be but one and the same law of ar 

 rangement for the results of our observations, measurements, 

 and so on, in these statistical enquiries. That is, he as 

 sumes that whenever we get a group of such magnitudes 

 clustering about a mean, and growing less frequent as 



1 As regards later statistics on the Secretary (Mr C. Eoberts) that their 



same subject the reader can refer to statistics are &quot;unique in range and 



the Eeports of the Anthropometrical numbers&quot;. They embrace not merely 



Committee of the British Association military recruits like most of the 



(1879, 1880, 1881, 1883 ; especially previous tables but almost every 



this last). These reports seem to class and age, and both sexes. More- 



me to represent a great advance on over they refer not only to stature 



the results obtained by Quetelet, and but to a number of other physical 



fully to justify the claim of the characteristics. 



