1836.] Method of putting music on organ barrels. 49 



4. — It is also plain that from the divisions on the plate the 

 length of any note may be readily ascertained ; thus two 

 crotchets may be taken for one minim ; three quavers for a 

 dotted crotchet ; three semiquavers for a dotted quaver ; three 

 crotchets for a dotted minim, and so on for notes of every 

 description. 



5. — In fig. 1 it will be seen that a small portion of the 

 .circumference of the circles is intended to be left free, which 

 portion is indicated by the lines a, b : this space is intended 

 for the purpose of making a momentary pause between the 

 end of a tune and its recommencement. 



6. — What has been stated refers only to common tunes 

 which an organ barrel continues to repeat until it is shifted 

 or adjusted to play another tune ; but as it has been shown 

 that the organ described, provides for playing the barrel con- 

 tinuously throughout its whole length, shifting it horizon- 

 tally as it revolves on its own axis, it is evident that the fore- 

 going divisions on the copper plate will not answer in this 

 case, because a small portion of the circumference (a, b) is 

 left undivided. I therefore made another series of circles on 

 the opposite side of the copper-plate, and the divisions on 

 them occupied the full circumference of each circle, but in 

 other respects the divisions were the same as the foregoing. 



7. — This plate is mounted on a brass axis, as shown in fig. 

 2, where c represents the axis, perforated at one end to re« 

 ceive the axis of the barrel, and d the flaunch of the axis to 

 which the plate x is screwed. The pieces e s g, fig. I, are 

 both attached to the axis, and are moveable around it. The 

 piece e, has a grove in it with a shifting point, f, which may- 

 be fixed so as to be applied to any circle of divisions on the 

 plate ; and the piece g, is simply a stop to the shifting point 



A, h, fig. 2, are screws to keep steady and attach the barrel 

 to the division plate, 



8. — The axis c, c, fig. 2, carries two series of groves k, m, 

 on it : the one, k consisting of 10 circular separate groves to 

 serve as a guide to the barrel in setting single tunes, the 

 other, m, being a spiral grove or screw of 10 revolutions in- 

 tended as a guide to the barrel when putting on it music to 

 play continuously till the barrel shifts. The distance of these 



