Human beings were used for a long time to fill these lungs--blowers working away with hands and feet.

We do much better now.

The great organ in Albert Hall, London, is supplied with air by steam which assures the organist an inexhaustible supply.

Other instruments use gas engines which are more manageable.

Then, there is the hydraulic system, which is very powerful and easily used, for one has only to pull out a plug to set the bellows in motion.
These mechanical systems, however, are not entirely free from accidents.
I discovered that fact when I was concluding the first part of the _Adagio_ in Liszt's great _Fantaisie_ in the beautiful Victoria Hall in Geneva.