CHARLES B. WARRING, PH.D. 129 



the centre of the earth. Finally I rise still higher in my 

 generalization, and say that all bodies on the earth, or at 

 a distance from it however great, if free to move, do 

 actually approach each other. Farther observation es- 

 tablishes the fact that such bodies, /. e., unsupported 

 and free to move, approach each other with varying 

 speed. If one is 100 times more massive than the other, 

 the smaller will travel 100 feet to the larger' s one. If 

 we vary the distance between them, we find that at three 

 times the distance apart the speed of each is but one-ninth 

 as great as it would have been had their distance been un- 

 changed. And from this we get the grand generalization 

 that the velocity due to gravitation varies directly as the 

 masses, and inversely as the square of the distance. 



In ways more or less similar, we deduce other physical 

 laws, i. e., statements of the order of sequence of physi- 

 cal phenomena. But the mind refuses to rest satisfied 

 with knowing in what order phenomena succeed each 

 other. To say that a certain thing took place, because 

 some other thing preceded it, gives little satisfaction to 

 our desire for information. We persist in believing that 

 there is some invisible efficient some thing connecting 

 antecedent and consequent. In this way it has come 

 about that Law is spoken of as if it were itself an entity, 

 a force capable of bringing about results, from which 

 there has sprung much confusion and false reasoning, 

 that in the poverty of language is perhaps unavoidable. 

 I shall be compelled in the paper I am about to read to 

 conform to this usage, but I hope in needful cases to 

 make clear the proper distinction. 



Of Physical Laws, in the complex sense of underlying 

 forces, and orders of sequence, the first, perhaps, in im- 

 portance, certainly the first in the wideness of its influ- 

 ence, is gravitation, acting at all distances, leaping across 

 the interstellar spaces with a speed more than 50,000,000 

 times greater than that of light. It passes through bodies, 



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