Descriptioji of asel/performiiigharrelorgan. 349 



iBight be played and repeated with as great facility as 

 longer pieces; the end to be accomplished was effected 

 thus : 



10.— In plan figure 4 at the left hand bottom corner, 

 13, represents a small steel slide, or inclined plane, 

 against which the axis of the wheels 11, 12, works, one 

 shoulder of the axis being pressed against the slide by 

 the spring 14. If this slide is drawn out, the spring 

 presses the axis and the wheels on it towards 19, by 

 which means the teeth of the wheel 11 escape from the 

 teeth of the pinion 10 (technically, the wheel 11 is 

 thrown out of geer) so that the snail 12 is left at liberty, 

 and is no longer acted on by the machinery. At 19 the 

 axis carries a hand, or pointer, and there is a dial plate 

 (not shown) divided into 10 divisions, so that a barrel 

 being used with 10 short tunes on it, the setting of the 

 pointer to any number on the dial, will play a corres- 

 ponding tune on the barrel; for although the wheels 10 

 and 11 are separated, and the snail has been moved a 

 little, sideways, yet being made wide on the edge it 

 still regulates the barrel, by means of the cylindrical 

 steel rod, b, in figure 5, the end of which is seen pro- 

 jecting at 16 in figure 4, and touching the face edge of 

 the snail wheel. This rod always touches the snail, so 

 that the snail is a regulator to the barrel, whether the 

 snail is set by the hand and afterwards remains inac- 

 tive, or whether it has a continual movement by. the in- 

 tervention of the wheel work : — Whenever a barrel is put 

 in the organ having 10 short tunes on it, this slide 13 

 must be pulled out, and the snail set to some division on 

 the dial plate, but when a barrel containing a long piece 

 of music, or 3 or 4 shorter pieces playing consecutively 

 is used, then the slide must be thrust in so that the snail 

 may be moved by the machinery. — This however is not 

 done at random, the pointer must point to, o, on the 



