CAUSE OF THE TIDES. 131 



a sublime scale to develop the electro-mechanical 

 action and reaction between the earth and moon, 

 and other heavenly bodies. The circulation of 

 electric currents in closed circuits may be applied 

 to explain the 



SIMULTANEOUS RISE OF TIDES ON OPPOSITE SIDES 

 OF THE EARTH. 



Previous illustrations show that the globe of 

 the earth is a powerful electro-magnet, excited by 

 the paramount electro-magnetic power of the sun, 

 and with its polarity determined through the solar 

 action. As stronger magnets determine the di- 

 rection of electric currents circulating about fee- 

 bler ones, the earth unquestionably determines 

 the direction of the currents circulating about its 

 satellite, the moon, to move in a similar direction 

 about the side nearest to the earth, as represented 

 by the arrows in Fig. 49. In 

 accordance with the principle of 

 action and reaction between elec- 

 trodes transmitting currents in 

 similar and in opposite directions, 

 reciprocal attraction ensues be- 

 tween the portion of molecules 

 constituting the nearest sides of 

 the moon and the earth ; and re- 

 ciprocal f repulsion between the Fig- 49- 

 portion of molecules constituting the side of the 

 moon nearest to the earth and those constituting 



