608 



ELECTRICAL CHIMES. 



The small bells required for this experiment, are like those used 

 as alarums in small clocks, and may be procured from a clockmaker 

 or purchased at the dealers in electrical apparatus. They should, if 

 possible, give out notes which have either the same pitch or differ 

 by a consonant interval, one being the third or fifth of the other 



FIG. 321 (A real size, B i real size). 



The clapper is made of a piece of brass wire, about 3 mm thick and 

 12 or 15 mm long, which is rounded at each end with the file, and then 

 flattened on both sides at one end, as shown in the figure. With a small 

 drill (see page 168, fig. 118) a hole is made in the flattened part 

 for the silk thread. Two small pieces of brass wire, I" 1 thick and 

 3 cm '5 long, are bent at one end into a ring of 4 mm diameter ; the 



