Correspondence of J, NicJdes. 255 



This investigation supposes the motion of E horizontal. This 

 is not usually the case. With a given rotation about a given 

 axis OP in the vertical plane through OE, we have seen that 

 there is needed a certain determinate force at E to produce 

 horizontal motion. Conversely then, for a given force at E, as 

 gravity, and a given initial rotation about E a determinate 

 horizontal impulse must be given to E, that is a determinate line 

 P in the plane P E must be at rest the first instantj if hori- 

 zontal motion is to be produced. 



"With any other initial impulse the motion is much complica- 

 ted. The resultant of the centrifugal forces is no longer in the 



^.„^ ^^^^v.w *^ ^V. ^^^Q 



vertical plane P E. Its direction is constantly varying. The 

 determination of the motion in this general case I do not propose 

 to undertake. My object has been to show in the simplest case, 

 and by methods not involving the processes of analysis, tlie ac- 

 tion of a vertical force producing horizontal motion of the center 

 of gravity. 



Art. XXI.- — Correspondence of M. Jerome NicJdh^ dated Paris 



March 7, 1857. 



Academy of Sciences. Distrihidion of Prizes. — Conformably to 

 usage, at the annual meeting of the Academy opening the new 

 year, a eulogy was pronounced by the Perpetual Secretary on 

 one of the former members ; and this year, the subject was the 

 mathematician Coriolis, who died September 18, 1843. ITis 

 titles to this honor and the remembrance of posterity are of 

 more than one kind. He contributed largely to the progress of 

 applied 'mechanics, by presenting in a new light the subject of 

 living forces ; in defining precisely what should be understood by 

 the worJc of a machine; in being the first to substitute for the con- 

 sideration of bodies taken in mass, the consideration of them as 

 composed of distinct molecules. 



^ Prizes were distributed by the Academy for different ques- 

 tions that had been pre\nousiy proposed, the more important of 

 which we mention, premising that the subjects were open to the 

 scientific men of all countries. 



The great prize for mathematical science was given to a 

 Q-erman, M. Kummer, for his Researches on complex numbers 

 consisting of roots of unity and of whole numbers. One of the 

 grand prizes in physical science was given to Professor Bronn at 

 Heidelberg, for an extensive work made in reply to the follow- 

 ing questions : — 1. What are the laws of distribution of fossil 

 organized bodies in the different sedimentary strata as regards 

 their order of superposition; 2. What as to their successive or 



simultaneous appearance or disappearance ; 8- What the rela^ 



