The Recent Revolution in Organ Building | Page 5

correspond, the stop is said
to be in. Thus it is that when no stops are drawn no sound is produced,
even although the wind-chest be full of air and the keys played upon.

This wind-chest with the slider stop control is about all that is left to us
of the old form of key action. The pallets were connected to the keys by
a series of levers, known as the tracker action.
There were usually six joints or sources of friction, between the key
and the pallet. To overcome this resistance and close the pallet required
a strong spring. Inasmuch as it would never do to put all the large pipes
(because of their weight) at one end of the wind-chest, they were
usually divided between the two ends and it became necessary to
transfer the pull of the keys sideways, which was done by a series of
rollers called the roller-board. This, of course, increased the friction
and necessitated the use of a still stronger spring. That with the
increased area of the pallet is why the lower notes of the organ were so
hard to play. And to the resistance of the spring must also be added the
resistance of the wind-pressure, which increased with every stop drawn.
When the organ was a large one with many stops, and the keyboards
were coupled together, it required considerable exertion to bring out the
full power of the instrument; sometimes the organist had to stand on the
pedals and throw the weight of his body on the keys to get a big chord.
All kinds of schemes were tried to lighten the "touch," as the required
pressure on the keys is called, the most successful of which was
dividing the pallet into two parts which admitted a small quantity of
wind to enter the groove and release the pressure before the pallet was
fully opened; but even on the best of organs the performance of music
played with ease upon modern instruments was absolutely impossible.
CHAPTER III.
THE DAWN OF A NEW ERA--THE PNEUMATIC LEVER.
Just as we no longer see four men tugging at the steering wheel of an
ocean steamer, the intervention of the steam steering gear rendering the
use of so much physical force unnecessary, so it now occurred to an
organ-builder in the city of Bath, England, named Charles Spachman
Barker,[1] to enlist the force of the organ wind itself to overcome the
resistance of the pallets in the wind-chest. This contrivance is known as
the pneumatic lever, and consists of a toy bellows about nine inches

long, inserted in the middle of the key action. The exertion of
depressing the key is now reduced to the small amount of force
required to open a valve, half an inch in width, which admits wind to
the bellows. The bellows, being expanded by the wind, pulls down the
pallet in the wind-chest; the bellows does all the hard work. The
drawing on the next page, which shows the lever as improved by the
eminent English organ-builder, Henry Willis, shows the cycle of
operation.
When either the finger or foot is pressed upon a key connected with k,
the outer end of the back-fall gg is pulled down, which opens the pallet
p. The compressed air in a then rushes through the groove bb into the
bellows cc, which rises and lifts with it all the action attached to it by l.
As the top of the bellows cc rises, it lifts up the throttle-valve d
(regulated by the wire m) which prevents the ingress of any more
compressed air by bb. But the action of the key on gg, which opened
the pallet p, also allowed the double-acting waste-valve e to close, and
the tape f hangs loose. The compressed air, therefore, as it is admitted
through bb cannot escape, but on the other hand when the key releases
the outer end of g, and lets it rise up again, the tape f becomes tightened
and opens the waste-valve, the bellows cc then drops into its closed
position.
[Illustration: Fig. 3. The Pneumatic Lever]
The organ touch could now be made as light as that of a pianoforte,
much lighter than ever before.
This epoch-making invention, introduced in 1832, rendered possible
extraordinary developments. It was at first strangely ignored and
opposed. The English organ-builders refused to take it up. Barker was
at length driven to France, where, in the person of Aristide
Cavaillé-Coll, he found a more far-seeing man.
After Cavaillé-Coll had fully demonstrated the practical value of
Barker's invention, Willis and others joined in its development, and
they contemporaneously overcame all difficulties and brought the
pneumatic action into general favor.

This process, of course, took time, and up to about fifty years ago
pneumatic action was found only