SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE. 



. 2-iO 



PROBLEMS OF ROTARY MOTION 



PRESENTED BY 



THE GYROSCOPE, 

 THE PRECESSION OF THE EQUIIv^OXES, 



Aim 



THE PENDULUM. 



BT 



Brevet Maj.-Gen. J. G. BARNARD, 



COLONEL OP ENOrNEERS U. S. -A., A.M., LL.D., MEMBER OF NATIONAL ACADEMY OP SCIENCES. 



[ACCEPTED FOR PDB LIGATION, OCTOBER, 1871.] 



