518 Prof. R. Clausius on the Transmission of 



Thus if p f denote prob. that it happens in none, p^ in one, 

 p' e in e times, 



P'o : p\ : P r 2 : • • • • P'e • • • • P'r 



= 1 : r 



r . (r — 1) r . (r— 1) . . . (r—e + 1) 



■ i2 : — n* 



The ratio is that of the terms in the expansion of (1 + l) r . 



Hence it is clear that, by the Theory of Probability, the 

 occurrence of an event in the past tells us absolutely nothing 

 as to its occurrence in the future. Also the larger the number 

 of times we include in our expectation, the less should be 

 our expectancy. 



Our ignorance of the future is left therefore just what it was 

 so far as any mere counting of cases in the past is concerned. 

 The determination to be taught by facts, and facts only, to 

 bring no preconceptions for the interpretation of those facts, 

 cuts us off from all means of making advance to the new facts 

 which are our quest. Presuppositions of knowledge, not of 

 ignorance, are what we want. The latter is perfectly expressed 

 in the statement that all constitutions of the Universe are 

 equally possible. The principles of Inductive Science are the 

 former. These assert that, so far from all constitutions of 

 the Universe being equally possible, one only is possible and 

 also necessary. Hence our business in observing Nature is 

 not the calculation of chances but the investigation of signs 

 of order, the knowledge of which shall enable us to infer 

 from them that one possible and necessary order of events. 



LIX. On the Theory of the Transmission of Power by 

 Dynamo-electrical Machines. By Prof. R. Clausius*. 



§ 1. Equations which hold for individual Machines. 



IN a paper recently publishedf I deduced two equations 

 which serve to determine the work of the ponderomotive 

 and of the electromotive force for a dynamo-electrical machine 

 in operation, and which are as follows: — 



■-kU' + Ai)-' , -(' + .raHl i • ' m 



In this T is the work of the ponderomotive force in unit of 



* Translated from a separate impression, communicated by the Author, 

 from the Annalen der Physik und Chemie, Band xxi., 1884. 

 t Phil. Mag. anted) p. 46. 



