CLOCK WEIGHT. 



Fig. II. 1 



The manner in which the object is attained by bevelled wheels 

 will be evident by inspecting fig. 9. The teeth in this case are 

 formed upon a surface inclined to the axis at an angle of 45, and 

 the two axles make with each other consequently an angle of 90. 



In the crown wheel A, fig. 10, the teeth are raised upon the 

 edge parallel to the axis, and work in the teeth or leaves of a 

 wheel or pinion B, whose axle is at right angles to that of A. 



In clockwork, the crown wheel is the expedient used for this 

 purpose, bevelled wheels being generally preferred in larger and 

 heavier applications of wheelwork. 



28. It has been already 

 stated that the moving 

 power applied to clock or 

 watchwork is either a 

 weight or a mainspring. 



If a weight be the mov- 

 ing power, it is suspended 

 to a cord which is coiled 

 upon a drum fixed upon 

 an horizontal axis, the first $ 

 wheel of the train which \ 

 gives motion to the hands 

 being fixed on the same 

 axis, so that it shall turn 

 when the drum turns. 



Such an arrangement is 

 represented in fig. 11, where 

 A B is the drum, c D the 

 wheel attached to it and 

 moved by it, w the weight 

 which is the moving power 

 suspended to the cord E, 

 which is coiled upon the 

 drum A B. The end, r, of 

 the axis of the drum pro- 

 jecting beyond it, is made 

 square, so as to receive a 

 key made to fit it, by which 

 it is turned, so as to coil 

 the cord upon the axis, 

 when it has been uncoiled by the descending motion of the weight. 



* This, and most of the succeeding diagrams have been copied from the 

 excellent work "Cours Elementaire de Mecanique," par Charles Delaunay 

 Victor Masson Paris, 1854, with the permission of the author and 

 publisher. 



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