48 [Ja:>\ 



Y I, —Met hod of putting music on organ barrels. — By . 

 Lieutenant J. Braddock. 



( Continued from page 354 of the 2d vol.) 



1 . — I shall now explain the manner in which the music 

 was put on the organ barrels. 



2. — In the first place, the principle on which the proceed* 

 ing is founded, is this. — Suppose a common tune is to set? 

 the number of bars it may contain may be 18. 20. 24. or some 

 other number if in common time ; or double the number if it 

 be in |, £ or triple, or waltzing time. Whatever be the num- 

 ber of bars which the tune may contain, that number is the 

 number of divisions which the circumference of the organ 

 barrel must be divided into, so that when the barrel has com- 

 pleted one revolution on its axis, the tune will be finished, 

 and ready to commence playing again. These divisions must 

 be sub-divided, and as each whole division represents one bar 

 of the tune, the sub-divisions represent crotchets, minims^ 

 and the several notes of which the tune consists. 



3. — This is the principle: the method in which it was re- 

 duced to practice was to procure a plate of copper of about 

 a foot in diameter, on one side of which I drew eight separate 

 pairs of circles, one pair of which only is shown in fig. 1 ; I 

 divided each pair of circles into 12. 13. 14. 15. 16. 18. 20 and 

 22 parts, and each of these parts was sub-divided into four 

 parts in one of the circles, and into three parts in the other 

 circle. These two divisions gave the several descriptions of 

 time as C, \> &c |, f, |, &c. for tunes consisting of the fore- 

 going numbers of bars ; and the sub-division of four parts 

 represented the four crotchets in the bar of common time, 

 and the sub-division of three parts the three notes making a 

 bar of 1 or | time. These sub-divisions were again divided 

 to provide for quavers, semiquavers, &c. so that from these 

 divisions on the plate when attached to the organ barrel, it is 

 plain that the length or value of each note could be duly pro- 

 portioned, and that the accuracy with which a tune was set 

 off on the organ barrel would be equal to the accuracy with 

 which the plate had been divided. 



