CHAP, v.] THE ORGAN. 197 



instrument of such gigantic proportions, and the ventil system of 

 bringing on or shutting off an entire family or group of registers has 

 given place to the vacuum pneumatic composition pedals acted upon 

 by the feet, which arrange the " tone colour" of the foundation and 

 mutation stops and accessory finger key-buttons by which the 

 performer is enabled to see his registers and comprehend his combi- 

 nations, a most important matter when it is remembered that, in 

 instruments of the first magnitude, the attention of the performer 

 is more or less absorbed between the -difficulties attendant upon 

 mechanical changes and the musical rendering of the piece. 



We may conclude our 'description of wind instruments with a short 

 reference to the cylinder organ known under the popular name of 

 the Barbary organ (it should be Barbari organ, and not Barbary. 

 Barbari is really the name of the maker in Modena who invented 

 this automatic instrument). By turning a handle, a cylinder, furnished 

 with " pins " of various lengths, is rotated, -which causes the keys of a 

 clavier to move. Corresponding to those keys is a mechanism which 

 sets a series of stops in action, the pipes of which put into vibration 

 by the air of a bellows, speak, and can thus reproduce a piece of 

 music. 



Besides the small barrel-organs we see carried about the streets, 

 others of much greater dimensions have been made. Fig. 138 repre- 

 sents one of these. They are doubtless of no great value with regard 

 to perfect tone, and the music they play is not always very agree- 

 able to the ear of dilettanti, but they serve to popularize in country 

 and town the most beautiful airs, overtures, marches from operas, 

 and symphonies. On this account they certainly deserve to be 

 mentioned. 



