644 



THE APPLICATIONS OF PHYSICAL FORCES. [BOOK v. 



has a reverser, the details of which are represented on the right of the 

 figure a wheel R', moved by a pin on the ratchet-wheel, carries on its 

 radii some pegs which press on the brancheaof a forked lever/, and make 



FIG. 422. Hipp's electric clock: outside view. 



FIG. 423. Details of the regulating and 

 distributing mechanism. 



it oscillate about its point of support. Two spring bands, fixed to the 

 other branch of the lever, oscillate in this way about a mean position, 

 and so one after the other establish contact first with the positive and 

 then with the negative pole of the battery. 



