A REVOLUTION IN WIND SUPPLY.
Prior to the construction of the above-named organ at Birkenhead,
England, it had been the custom to obtain or regulate the pressure of
wind supplied to the pipes by means of loading the bellows with
weights. Owing to its inertia, no heavy bellows weight can be set into
motion rapidly. When, therefore, a staccato chord was struck on one of
these earlier organs, with all its stops drawn, little or no response
was obtained from the pipes, because the wind-chest was instantly
exhausted and no time was allowed for the inert bellows weights to fall
and so force a fresh supply of air into the wind-chests.
BELLOWS SPRINGS VERSUS WEIGHTS.
In one of Hope-Jones' earliest patents the weights indeed remain, but
they merely serve to compress springs, which in turn, act upon the top
of the bellows.
Before this patent was granted he had, however, given up the use of
weights altogether and relied entirely upon springs.
This one detail--the substitution of springs for weights--has had a
far-reaching effect upon organ music. It rendered possible the entire
removal of the old unsteadiness of wind from which all organs of the
time suffered in greater or less degree. It quickened the attack of
the action and the speech of the pipes to an amazing extent and opened
a new and wider field to the King of Instruments.
In the year 1894 John Turnell Austin, now of Hartford, Conn., took out
a patent for an arrangement known as the "Universal air-chest." In
this, the spring as opposed to the weight is adopted. The Universal
air-chest forms a perfect solution of the problem of supplying prompt
and steady wind-pressure, but as practically the same effect is
obtained by the use of a little spring reservoir not one hundredth part
of its size, it is questionable whether this Universal air-chest,
carrying, as it does, certain disadvantages, will survive.
INDIVIDUAL PALLETS.
Fifty years ago the pallet and slider sound-board was well nigh
universally used, but several of the builders in Germany, and Roosevelt
in this country, strongly advocated, and introduced, chests having an
independent valve, pallet or membrane, to control the admission of wind
to each pipe in the organ.[1]
In almost all of these instances small round valves were used for this
purpose.
A good pallet and slider chest is difficult to make, and those
constructed by indifferent workmen out of indifferent lumber will cause
trouble through "running"--that is, leakage of wind from one pipe to
another. In poor chests of this description the slides are apt to
stick when the atmosphere is excessively damp, and to become too loose
on days when little or no humidity is present.
Individual pallet chests are cheaper to make and they have none of the
defects named above. Most of these chests, however, are subject to
troubles of their own, and not one of those in which round valves are
employed permits the pipes to speak to advantage.
Willis, Hope-Jones, Carlton C. Michell and other artists, after lengthy
tests, independently arrived at the conclusion that the best tonal
results cannot by any possibility be obtained from these cheap forms of
chest. Long pallets and a large and steady body of air below each pipe
are deemed essential.[2]
HEAVY WIND PRESSURES.
As previously stated, the vast majority of organs built fifty years ago
used no higher wind pressure than 3 inches. Hill, in 1833, placed a
Tuba stop voiced on about 11 inches in an organ he built for Birmingham
Town Hall (England), but the tone was so coarse and blatant that such
stops were for years employed only in the case of very large
buildings.[3] Cavaillé-Coll subsequently utilized slightly increased
pressures for the trebles of his flue stops as well as for his larger
reeds. As a pioneer he did excellent work in this direction.
To Willis, however, must be attributed greater advance in the
utilization of heavy pressures for reed work. He was the first to
recognize that the advantage of heavy wind pressure for the reeds lay
not merely in the increase of power, but also in the improvement of the
quality of tone. Willis founded a new school of reed voicing and
exerted an influence that will never die.
In organs of any pretensions it became his custom to employ pressures
of 8 to 10 inches for the Great and Swell chorus reeds and the Solo
Tubas in his larger organs were voiced on 20 or 25 inches.
He introduced the "closed eschallot" (the tube against which the tongue
beats in a reed pipe) and created a revolution in reed voicing. He has
had many imitators, but the superb examples of his skill, left in
English Cathedral and town hall organs, will be difficult to surpass.
Prior to the advent of Hope-Jones (about the year 1887) no higher
pressure than 25 inches had, we believe, been employed in any organ,
and the vast majority of instruments were voiced on pressures not
exceeding 3 inches. Heavy pressure flue voicing was practically
unknown, and in reeds even Willis used very moderate pressures, save
for a Tuba in the case of really large buildings.
Hope-Jones showed that by increasing the weight of metal, bellying all
flue pipes in the centre, leathering their lips, clothing their flues,
and reversing their languids, he could obtain from heavy pressures
practically unlimited power and at the same time actually add to the
sweetness of tone produced by the old, lightly blown pipes. He used
narrow mouths, did away with regulation at the foot of the pipe, and
utilized the "pneumatic blow" obtained from his electric action.
He also inaugurated "an entirely new departure in the science of reed
voicing." [4]
He employs pressures as high as fifty inches and never uses less than
six. His work in this direction has exercised a profound influence on
organ building throughout the world, and leading builders in all
countries are adopting his pressures or are experimenting in that
direction.
Like most revolutionary improvements, the use of heavy pressures was at
first vigorously opposed, but organists and acousticians are now filled
with wonder that the old low-pressure idea should have held sway so
long, in view of the fact that very heavy wind is employed for the
production of the best tone from the human voice and from the various
wind instruments of the orchestra.
Karl Gottlieb Weiglé, of Stuttgart, was a little in advance of many of
his confrères in using moderately heavy pressures, but he departed from
the leather lip and narrow mouth used by Hope-Jones and has obtained
power without refinement.
In employing these heavy pressures of wind, increased purity and beauty
of tone should alone be aimed at. Power will take care of itself.
MECHANICAL BLOWERS.
The "organ beater" of bygone days was invariably accompanied by the
"organ pumper," often by several of them. There is a well-known story
of how the man refused to blow any longer unless the organist said that
"_we_ had done very well to-day." The organ pumper's vocation is now
almost entirely gone, especially in this country, although we know of
organs in England which require four men "to blow the same" unto this
day.
When Willis built the great organ in St. George's Hall, Liverpool, in
1855, he installed an eight-horsepower steam engine to provide the wind
supply. There is a six-horse steam engine in use in Chester Cathedral
(installed 1876).
Gas and petrol (gasoline) engines have been used extensively in
England, providing a cheaper, but, with feeders, a less controllable,
prime mover. By far the commonest source of power has been the water
motor, as it was economical and readily governed, and as water pressure
was generally available, but the decline of the old-time bellows, with
the fact that many cities to-day refuse to permit motors to be operated
from the water mains, have given the field practically to the electric
motor, now generally used in connection with some form of rotary fans.
The principle of fans in series, first introduced by Cousans, of
Lincoln, England, under the name of the Kinetic Blower, is now accepted
as standard. This consists of a number of cleverly designed fans
mounted in series on one shaft, the first delivering air to the second
at, say, 3-inch pressure, to be raised another step and delivered to
the next in series, etc., etc. This plan permits tapping off desired
amounts of air at intermediate pressures with marked economy, and as it
is slow speed, and generally direct connected with its motor on the
same shaft, it is both quiet and mechanically efficient.
[1] One object of this was to prevent what was called "robbing." While
the pressure of the wind might be ample and steady enough with only a
few stops drawn, it was found that when all the stops were drawn the
large pipes "robbed" their smaller neighbors of their due supply of
wind, causing them to sound flat. By giving each pipe a pallet or
valve to itself, the waste of wind in the large grooves was prevented.
Another object was to get rid of the long wooden slides, which in dry
weather were apt to shrink and cause leakage, and in damp weather to
swell and stick.
[2] A striking instance of the difference between the two kinds of
pallet can be seen in All Angels' Church, New York. The organ was
built originally by Roosevelt, with two manuals and his patent
wind-chest. In 1890 the church was enlarged and Jardine removed the
organ to a chamber some thirty feet above the floor and fitted his
electric action to the Roosevelt wind-chest. At the same time he
erected an entirely new Choir organ, in the clerestory, with his
electric action fitted to long pallets. The superiority of attack and
promptness of speech, especially of the lower notes, of the Choir over
the Great and Swell organs is marvelous. The same thing can be seen at
St. James' Church, New York, where the Roosevelt organ was rebuilt with
additions by the Hope-Jones Organ Co. in 1908.
[3] Some congregations could not stand them and had them taken out.
[4] Wedgwood: "Dictionary of Organ Stops," p. 167.