1D2 



matter is retained in its position by equal centrifugal and 

 centripetal forces. So that, when a molecule is withdrawn 

 from its position of equilibrium, it moves toward the'centre 

 of the earth till it finds its status. The centiipetal force is 

 under these circumstances the greater, and moves the mole- 

 cule towards the centre. But why with a constantly in- 

 creasing velocity ? According to Dr. Hickok's enunciation 

 of the first law of motion, which was a fair deduction from 

 from his first principles, the motion should manifestly be 

 uniform. But nature was very unkind, and so constituted 

 matter that a body falls with a constantly accelerated mo- 

 tion, instead of a uniform, in conformity with the author's 

 system. 



But, granting the author's premises, that in some way an 

 accelerated motion is produced, we are treated with one of 

 the most remarkable specimens of reasoning that it was 

 ever the lot of man to devise. He is endeavoring to make 

 out a priori what must be the rate of increase in the descent 

 of a falling body. " Take then," says he, " any body and 

 let it possess the degree of energy on the side opposite the 

 centre, and it must gravitate toward the centre. It must 

 pass through its measure of space or height, which we will 

 call H, in one moment. In passing through H, it has gained 

 (how it gained it, he does not tell us) the excess of energy 

 or gravity occupying that space, and must therefore have 

 now an excess of energy or gravity from the fall through 

 H that would make it fall the next moment through 2 H." 

 One would think that thus far he had proved quite satis- 

 factorily, that the body during the second moment would 

 fall through a space 2 H. The only objection to this con- 

 clusion is, that it is not true ; the fact being that it falls 

 through a space 3 H during the second moment. The au- 

 thor probably knew enough of mechanics to be aware of 

 this, and therefore struggles to adapt his eternal principles 

 to the fact. We understood him to mean that the body 

 moved during the first moment a space H, and in moving 



