THE PRECESSIOH OF THE KQCINOXES AND NUTATION AS RESULTING 

 FROM THE THEORY OF T11E GYROSCOPE. 



IN a ]):ij)cr published in the American Journal of Science, in 1857, nnd in Bar- 

 nard's American Journal of Education 1 [No. 9] of the same year, I remarked: 



"The analogy between the minute motions of the gyroscope and that grand 

 phenomenon exhibited in the heavens, the 'precession of the equinoxes,' is often 

 remarked. In an ultimate analysis, the phenomena, doubtless, are identical," &c. 



It is the object of the present paper to deduce the analytical expressions of this 

 phenomenon directly from the theory of the gyroscope. 



A brief summary of the processes used and results arrived at in the paper referred 

 to is necessary as a preliminary. 



Let A, /.'. f ', I) (Fig. 1) be a solid body of any shape, retained by the fixed point 

 (within or without its mass). Ox, Oy, and Oz are the three co-ordinate axes, 



Fig. 1. 



fixed in *pace, to which the motion of the body is referred, ftp,, Oy,, Oz, are the 

 three principal axes belonging to the point O, and which, of course, partake of the 



1 " The Phenomena of the Gyroscope Analytically Examined." 

 1 October 187L f 1 ) 



