!0 KINETICS OF A RIGID BODY. [290 



through this point P parallel to the principal axes of the body ; deter- 

 mine the directions of the principal axes at P, and show that these 

 directions coincide with the normals of the three surfaces passing 

 through P and confocal to the fundamental ellipsoid of the body. 



290. A brief account of the theory of moments of inertia will be found 

 in B. WILLIAMSON, Integral Calculus, 6th ed., London, Longmans, 1891, 

 pp. 291-312. The subject is discussed very fully in E. J. ROUTH, j 

 Dynamics of a system of rigid bodies, Part I., 5th ed., London, Mac- j 

 millan, 1891, pp. 1-49; and in B. PRICE, Analytical mechanics, Vol. II.,. 

 2d ed., Oxford, Clarendon Press, 1889, Chapter IV. The student will 1 

 also consult with advantage W. SCHELL, Theorie der Bewegung und der 1 

 Krdfte, Vol. I., 2d ed., Leipzig, Teubner, 1879, PP- 100-143, an <i 1 

 A. CAYLEY, Report on the progress of the solution of certain special 

 problems of dynamics, in the Report of the 32d meeting of the British 

 Association, for 1862, London, Murray, 1863, pp. 223-229. 



