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 in a few organs of large calibre.
The recent revolution in organ building and in organ tone, of which
this book treats, was founded upon the pneumatic and electro-pneumatic
actions invented by Barker.[2]
It is safe to say that the art of organ building has advanced more
during the last fifty years than in any previous three centuries. We
are literally correct in saying that a veritable revolution has already
been effected--and the end is not yet.
As leaders in this revolutionary movement, three names stand out with
startling prominence--Henry Willis, Aristide Cavaillé-Coll and Robert
Hope-Jones.
Others have made contributions to detail (notably Hilborne L.
Roosevelt), but it is due to the genius, the inventions and the work of
those three great men that the modern organ stands where it does to-day.
We propose:
1. To enumerate and describe the inventions and improvements that have
so entirely transformed the instrument;
2. To trace the progress of the revolution in our own country; and,
3. To describe the chief actors in the drama.
In the middle of the last century all organs were voiced on light wind
pressure,[3] mostly from an inch and a half to three inches. True, the
celebrated builder, William Hill, placed in his organ at Birmingham
Town Hall, England, so early as 1833, a Tuba voiced on about eleven
inches wind pressure, and Willis, Cavaillé-Coll, Gray and Davison, and
others, adopted high pressures for an occasional reed stop in their
largest organs; yet ninety-nine per cent. of the organs built
throughout the world were voiced on pressures not exceeding three and
one-half inches.
In those days most organs that were met with demanded a finger force of
some twenty ounces before the keys could be depressed, when coupled,
and it was no uncommon thing for the organist to have to exert a
pressure of fifty ounces or more on the bass keys. (The present
standard is between three and four ounces. We are acquainted with an
organ in New York City which requires a pressure of no less than forty
ounces to depress the bass keys.)
The manual compass on these organs seldom extended higher than f|2| or
g|3|, though it often went down to GG.[4]
It was common to omit notes from the lower octave for economy's sake,
and many stops were habitually left destitute of their bottom octaves
altogether. Frequently the less important keyboards would not descend
farther than tenor C.[5]
The compass of the pedal board (when there was a pedal board at all)
varied anywhere from one octave to about two and a quarter octaves.
The pedal keys were almost invariably straight and the pedal boards
flat.
[Illustration: Fig. 4. Nomenclature of Organ Keyboard]
[1] The invention of the pneumatic lever has been claimed for Mr.
Hamilton, of Edinburgh, Scotland. It is, however, generally credited
to Barker and known as the "Barker pneumatic lever." (See also note
about Joseph Booth, page 129.)
[2] Barker was also associated with Péschard, who in 1864 patented
jointly with him the electro-pneumatic action. (See page 37.)
[3] The pressure of the wind supplied by the old horizontal bellows is
regulated by the weights placed on top. The amount of this pressure is
measured by a wind-gauge or anemometer invented by Christian Förmer
about 1677. It is a bent glass tube, double U shaped, into which a
little water is poured. On placing one end of it fitted with a socket
into one of the holes in the wind-chest (in place of a pipe) and
admitting the wind from the bellows the water is forced up the tube,
and the difference between the level of the surface of the water in the
two legs of the tube is measured in inches. Thus, we always talk of
the pressure of wind in an organ as being so many inches.
[4] The organ in Great Homer Street Wesleyan Chapel, Liverpool,
England, had manuals extending down to CCC. It was built for a man who
could not play the pedals and thus obtained 16 ft. tone from the keys.
The old gallery organ in Trinity Church, New York, also has this
compass.
[5] Tenor C is the lowest note of the tenor voice or the tenor violin
(viola). It is one octave from the bottom note of a modern organ
keyboard, which is called CC. The lowest note of the pedal-board is
CCC. Counting from the bottom upwards on the manual we have,
therefore, CC (double C), C (tenor C), c (middle C), c|1| (treble C),
c|2| (C in alt) and c|3| (C in altissimo). This is the highest note on
the keyboard of 61 keys. According to the modern nomenclature of the
_pianoforte_ keyboard this note is c|4|, and is frequently so stated
erroneously in organ specifications.
GG is four notes below CC, _the break in the scale coming between GG
and FFF_. Tenor C is an important note to remember. Here is where the
cheap builder came in again. He cut his stops short at tenor C,
trusting to the pedal pipes to cover the deficiency.
* * * * * *
[Illustration: PROSPER-ANTOINE MOITESSIER, INVENTOR OF TUBULAR
PNEUMATIC ACTION]
In the year 1845, Prosper-Antoine Moitessier, an organ-builder of
Montpellier, France, patented what he called "_abrégé pneumatique_," an
organ action in which all back-falls and rollers were replaced by tubes
operated by exhaust air. In 1850 he built with this action an organ of
42 speaking stops for the church of Notre Dame de la Dalbade at
Toulouse. This organ lasted 33 years. In 1866 Fermis, schoolmaster
and village organist of Hanterire, near Toulouse, improved on
Moitessier's action by combining tubes conveying compressed air with
the Barker lever. An organ was built on this system for the Paris
Exhibition of 1867, which came under the notice of Henry Willis, by
which he was so struck that he was stimulated to experiment and develop
his action, which culminated in the St. Paul's organ in 1872. (From
article by Dr. Gabriel Bédart in Musical Opinion, London, July, 1908.)