350 Description of a self performingharr el or gan, [Oct. 



dial plate^ and the barrel must be in a particular po- 

 sition. 



1 1 . — I now proceed to describe the mechanism for 

 working the bellows. 



12. — Figure 7, shows the arrangement drawn to ^ 

 scale of one fourth of the real size. — 1, is the barrel 

 upon which the line H figure 1 is wound ; 2 is the 

 wheel attached to the barrel, working into the wheel 3, 

 on the axis of which, 4, is placed working into 5 ; on 

 the axis of 5 a wheel 6 is fixed, and this wheel carries 

 the rod I [figures 1. 2.] that works the bellows, which 

 of course close and open, once, for every revolution of 

 the wheel. But as the motion would be irregular if the 

 train of wheel work stopped here, the wheel 6 works the 

 wheel 7, which gives motion to a fly wheel 8 six inches 

 in diameter with a rim of J an inch deep, and ^^^th of 

 an inch thick. This fly wheel makes the motion 

 smooth, and answers besides another useful purpose, 

 which will be presently explained. Figure 8, which is a 

 plan of the foregoing, will further show the positions of 

 the wheels, the digits answering to figure 7. Observe 

 that in figure 8, the small wheel 7 in figure 7, is under- 

 neath the wheel 6, and cannot therefore be shown in fi- 

 gure 8, but the axle of 7 runs parallel to and under the 

 axis of 5, 6, and at the extremity is fixed the fly wheel 8. 



13. — In every organ that I have seen there is a valve 

 fixed in the reservior L figure 1, so that when it rises 

 to a proper height, i. e. when it is filled with air, the 

 valve opens and lets the surplus air escape : otherwise, 

 if the bellows K figure 1, were overworked, the reser- 

 voir L would burst. And in the case of clock organs 

 although the reservoir might not be burst, [the machi- 

 nery not possessing suflicient power] yet the pipes 

 would be overblown, and be immediately put out of 

 tune. Now this escape of the surplus air is an evil in 



