THE CAUSE OF GRAVITATION 



tation manifests itself are well known. That it acts 

 upon all matter directly as the mass, and inversely as 

 the square of the distance between centres, and that 

 a falling body near this earth moves with a constantly 

 accelerating speed of nearly thirty-two feet per second. 

 But what is gravity ? What is the force that acts 

 and causes one mass of matter to move towards 

 another mass, or when in contact presses them forcibly 

 together? It is a question so difficult to answer 

 if it can, even in part, be answered at all that in 

 the modern text-books of Physics no attempt is made 

 to explain it. Prof. Barker, however, states: "A 

 study of other forms of attraction has resulted in con- 

 centrating the attention more closely upon the Ether 

 intervening between the two attracting bodies than 

 upon the bodies themselves. . . . Whatever the seat 

 of the energy, however, whether in the attracting 

 masses themselves or in the surrounding medium, 

 the general attraction which is exerted between masses 

 of matter has received the name of gravitation, while 

 that exerted between the earth and bodies upon its 

 surface is called gravity." 



The reasons why the study of the causes of gravi- 

 tation has made so little progress are twofold : First, 

 the knowledge of the laws that govern its action is so 

 accurate, and so fully satisfies all the demands for the 

 practical application thereof, that investigation into 



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