38 



Fig. 19. 



COMMON THINGS. 



CLOCKS AND WATCHES. 



CHAPTER III. 



Method of regulating a balance-wheel. 39. Recoil 

 escapement. 40. Cylindrical escapement. 41 . 

 Duplex. 42. Lever. 43. Detached. 44. Main- 

 taining power of a clock moved by a weight. 45. Of a watch 

 moved by a mainspring. 46. Weight or mainspring and pendulum 

 LAUDNER'S MUSEUM OP SCIENCE. D 33 



No. 74. 



