128 ANNUAL OF SCIENTIFIC DISCOVERY. 



by a steam-engine, consisting of a pair of oscillating cylinders. There 

 are besides twelve other bellows, or reservoirs, each giving its own appro- 

 priate pressure of air to those stops or pipes which it supplies. The pneu- 

 matic lever is applied to each of the manuals distinctly, and also distinctly 

 or separately to the manual couplers. To the pedal organ there is a double 

 set of penumatic levers ; but the most elaborate use of this power is found 

 in its application to the combination of stops ; here we have it exhibited 

 in a compound form to each organ individually, and to the whole collec- 

 tively, where by one operation the player is enabled to produce a combi- 

 nation of stops upon the entire instrument at once. This movement 

 appears in a series of six handsome gold- gilt knobs, placed immediately 

 under each set of manuals, at about two keys' distance from each other, 

 occupying a central position, always within reach of one or other of 

 the performer's thumbs. The pneumatic lever is also applied to the 

 opening and shutting of the swell louvres and some other less important 

 purposes. 



ON THE COLLECTION AND VALUE OF STATISTICAL INFORMATION. 



The Earl of Harrowby, President of the British Association, in his 

 annual address, thus adverts to the labors of the statistical section of that 

 body ; his remarks apply to all societies of like character, and especially 

 controvert the position of those who regard the accumulation of such 

 information as of little or no value : 



" Who shall separate political altogether from the influences of physical 

 geography, or ethnology from physiology, or the destinies of man upon 

 this globe from the study of his physical nature ? By its employment of 

 the doctrine of probabilities, one branch of statistics is brought into imme- 

 diate contact with the higher mathematics, and the actuary is thus enabled 

 to extract certainty in the gross out of uncertainty in the detail, and to 

 provide man with the means of securing himself against some of the worst 

 contingencies to winch his life and property are exposed. In fact, statis- 

 tics themselves are the introduction of the principle of induction into the 

 investigation of the affairs of human life an operation which requires the 

 exercise of at least the same philosophical qualities as other sciences. It 

 is not enough, in any case, merely to collect facts and reduce them into a 

 tabular form. They must be analyzed as well as compared ; the accom- 

 panying circumstances must be studied, (which is more difficult in moral 

 than in material investigations,) that we may be sure that we are (that is 

 to say, in reality calling the same things by the same names) treating of 

 the same facts under the same circumstances ; and all disturbing influences 

 must be carefully eliminated before any such pure experiment can be got 

 at as can fairly be considered to have established a satisfactory conclusion. 

 In some cases this is easier than in others. In regard to the probabilities 

 of life or health, for instance, there are, at least, no passions or prejudices, 

 no private interests at work, to interfere with the faithful accumulation of 



