Chase.] 4-90 [December. 



3. If M' and B" are required, (4), (9), (10), being supposed 

 correct, 



M' = .00144 (15) 



and the value of B" is the same as in (13). 



Other hypotheses might be made, but these are sufficient for 

 illustration. 



Even the widest discrepancy between theory and observation is 

 much less than might have been reasonably anticipated in measure- 

 ments of such extreme delicacy, and far within the limits of probable 

 error, as will be seen by the following synopsis : 



In regard to the first theoretical value of M", it may be observed 

 that it is very nearly equivalent to the mean between .000032, the 

 extreme excursion of the lunar tide, and .0000255, the mean tide. 



" TORRICELLI." 



Mr. Chase made some remarks, in explanation of the sub- 

 ject of the premium. 



In the fifth century before the Christian era, Leucippus and his 

 disciple Democritus taught that heat is the soul of the world, the 

 principle of life and intelligence, and that space is an infinite plenum, 

 pervaded by material atoms too minute to be perceptible to the 

 senses, which, by their constant motions, unions, and separations, 

 form the beginnings and ends of things. In this theory, which is 

 said to have been borrowed from the priests of Isis and Osiris, we 

 may trace the origin of the modern belief in a universal kinetic 

 aether, and of the attempts to resolve all forces into " modes of mo- 

 tion," which were practically inaugurated by our own countryman, 

 Benjamin Thompson, Count liumford, and which have been so suc- 

 cessfully prosecuted by Carnot, Seguin, Mayer, Colding, Joule, Grove, 

 and their collaborators. 



