P OLYTECHNIC ASSOCIATION. 893 



you please, and still you will find numbers true to those mechanical 

 properties. 



Admit the hypothesis, then, as in fact we have already proved it, 

 that the earth revolves round the sun on the value of the circumfer- 

 ence of the moon's orbit, and we then know the sun's distance, with- 

 out waiting till 1874 to learn the confused results of the vast outlay 

 for observing the transit of Venus ; and what is of much greater 

 importance, we have learned by this examination that because our 

 earth revolves about the sun, on the value of the circumference of the 

 moon's orbit, the earth being in the center, the earth, therefore, 

 moves evenly through space, as the center of that revolving orb, put 

 in motion by the attraction of magnetism (gravitation), and kept in 

 motion by the universal law of the sun's precession, and, therefore, 

 there is no such thing in nature as a projectile force, and especially 

 there is none in the motion of our earth round the sun. 



The President — What do you mean by the term " precession ; " do 

 you mean the precession of the equinoxes ? 



Mr. Parker — I mean the precession of the sun. In consequence of 

 the revolution of the sun in space, the earth is about twenty-three 

 hours and fifty-six minutes in revolving from star to star ; while it is 

 twenty-four hours in revolving from sun to sun. I hold that the sun, 

 in that case, goes oefore and takes the lesser tributary orbs along with 

 it, and that is the precession I refer to. 



The President — The precession of the equinoxes is only the result 

 of the earth's being an oblate spheroid. It would not exist, were the 

 earth a sphere ; and it has nothing to do with keeping the earth in 

 motion. 



Dr. J. W. Richards — It is evident that he does not mean the pre- 

 cession of the equinoxes, but I am at a loss to understand the term as 

 it is used in this paper. 



Mr. Parker — I consider the sun's advance, every day, as the sun's 

 precession or going before. We revolve opposite a fixed star in four 

 minutes less time than the sun. Does not that prove the sun is in 

 motion ? That is the precession I mean. 



Dr. P. H. Yan der Weyde — That is what is called the acceleration 

 of the stars. The sun lags behind, as it were ; is that the precession 

 you mean ; that is, supposed to be the cause of keeping the earth in 

 motion in its orbit ? 



Mr. Parker — Yes. 



Dr. Yan der Weyde — I should call it the result of the earth's motion 

 in its orbit. The earth must necessarily make one revolution more 



