Manchester Memoirs, Vol. xlvi. (1902), No. 10. 3 



Notwithstanding the numerous demonstrations that 

 have been given of the diurnal rotation of the earth on its 

 axis, the doctrine is comparatively of too recent origin in 

 the world's history to obtain universal acceptance, or even 

 by many of the educated classes. Considering that Roman 

 ecclesiasticism has, up to the present time, made no formal 

 pronouncement in favour of the doctrine, either by the 

 canonization of Copernicus and Bruno, or by the erection 

 of monuments to Kepler and Galilei, it is not surprising 

 that attempts should be made from time to time to revive 

 the simian idea of the immobility of the earth and the 

 geocentric system of the universe. These attempts may 

 afford amusement to some, or be thought unworthy of 

 attention by those engaged in the more profitable work of 

 enlarging the boundaries of science, but, from an educa- 

 tional point of view, they are not to be lightly dismissed, 

 as the greater part of man's knowledge is derived, not so 

 much from the evidence of things themselves, as from 

 those authorities who profess to have obtained such 

 evidence at first hand. 



The pendulum and gyroscopic experiments of 

 Foucault are the latest as well as the most brilliant 

 demonstrations of the axial rotation of the earth that have 

 yet been presented to the world. That they are the most 

 convincing is evident from the fact that the rotation can 

 be made visible in a room or below the surface of the 

 earth. It has also been further shown that the times of 

 the apparent rotation of the pendulum are in proportion 

 to the sines of the latitude. Thus the motion of the plane 

 of oscillation whereby the pendulum appears to turn 

 round the vertical line in the same direction as the 

 celestial bodies, i.e., in the opposite direction to that of 

 the rotation of the earth, would complete an entire re- 

 volution at the poles in twenty-four hours, the motion 



