no 



BODIES REVOLVED BY HEAT. 



This spectacle inspired awe, commingled with 

 admiration of the sublime display of Omnipotent 

 Power, as graphically described by the Psalmist : 

 " He bowed the heavens and came down. Dark- 

 ness was under His feet, and He moved on the 

 wings of the wind. He made darkness His secret 

 place, and the pavilion around about Him was 

 dark waters and thick clouds of the sky." 



The intense electric excitation transmitted 

 through the vortex of a tornado at Wallingford, 

 Connecticut, is described in a recent account as 

 follows : " In some mysterious manner, the hay 

 from a barn, taken up into the air, was set on fire, 

 and came down all blazing upon the ground." 



In the experiment made with the whirling mer- 

 cury, the direction of the whirl depends on the 

 ascending or descending direction of the electric 

 current ; and probably the same law governs the 

 direction of a whirling tornado. 



Further to illustrate the 

 rotation of a freely movable 

 conducting wire, or other 

 electrode, produced by a cur- 

 rent vertical to the horizontal 

 terrestrial currents, the slight 

 excitation of a thermo-elec- 

 tric current may be used ; as 

 in Fig. 31, which represents 



an arched wire frame, w A E, 



^^ 



Flf ' 3I ' supported on a pivot at A, 



