128 THE APPLICATIONS OF PHYSICAL FORCES. [BOOKII. 



carillons constitute an important improvement on the two other 

 systems. The carillon placed recently in the tower of Saint Germain 

 1'Auxerrois is of this kind. This is composed of forty-two bells of 

 different sizes. 



In the towns of the north of Europe, as at Bruges, for instance, 

 the striking of the public clocks at the hours and half-hours is 

 preceded by an air automatically played on the chimes. The famous 

 carillons of Bruges, Dunkerque, and other northern towns are con- 

 structed with a mechanism similar to that of musical boxes ; but the 

 cylinders are enormous, and the teeth on their surfaces lift up heavy 

 hammers which strike on a series of bells tuned to the notes of the 



FIG. 82. Somiantes. 



+ 



scale. Movement is given to the cylinders by wheelwork, which the 

 belfry clocks set in motion every hour or even at the halves and 

 quarters. To set these enormous machines in motion, it is necessary 

 to have weights of several hundreds and even thousands of kilo- 

 grammes carried by chains which are wound on drums by means of 

 a windlass. To wind them up daily, two or three men working from 

 half an hour to three hours are required. 



But this ancient system of chimes, which was itself an im- 

 provement on the primitive system represented in Fig. 83, has been 

 much simplified in the carillon at Saint Germain 1'Auxerrois 

 which we have just mentioned, and represented in Fig. 84.- This 



