Page:EB1911 - Volume 20.djvu/295

 the great organ, as is very commonly the case, the octaves are reached through two couplers. And, as couplers are not generally screwed up quite tight, the octaves are often not sufficiently put down to sound in tune. The choir to great sub-octave coupler was used chiefly as a substitute for a double on the great organ. It is common in organs of the transition period, but is not a good arrangement.

The pneumatic lever (fig. 13) consists of a small power bellows attached to each key, so that the depression of the key admits high-pressure wind to the power bellows. The power bellows then performs the work of opening the valves, &c. In large organs the work to be done would be beyond the reach of the most powerful finger without this device. Similar devices are sometimes applied to the compositions and other mechanical arrangements.

13.—Pneumatic Lever.

Pneumatic transmission, with many other mechanical devices, was invented by Willis. It consists of a divided pneumatic action. The pneumatic wind, instead of being at once admitted to the power bellows, is made to traverse a length of tubing, at the farther end of which it reaches the work to be done. This principle admits of application to divided organs, the pneumatic transmission passing under the floor, as in the organ at St Paul’s Cathedral.

Ventils are valves which control the wind-supply of the different groups of stops. They were much recommended at one time as a substitute for compositions. The practical difference is that compositions shift the stop-handles, so that one can always see what there is on the organ; ventils leave the stop handles unmoved, so that the player is liable to be deceived. Other inconveniences might be mentioned, but it is enough to say that practical opinion appears decidedly to condemn the use of ventils.

The original pedal boards of Germany were flat and of very large scale. The early practice in England was to make them very small, as well as of short compass. Of late the compass C—𝑓′, thirty notes, has been universally adopted with scales varying from 2 to 2 in. from centre to centre of the naturals; 2 in. is the scale now recommended. A large

number of organs have been provided with concave radiating pedal boards. The objections to this arrangement are mainly two: They present different scales at different distances from the front; and, except just in front, they become so narrow that the smallest foot can hardly put down the pedals singly. This renders difficult the old Bach style of playing, the essence of which consists in putting the feet over each other freely, so as to use the alternate method as much as possible; and this requires that the back of the pedal board shall be as available as the front.

The diversities of the arrangements of different organs present a great difficulty. The best players take a certain time to master the arrangements of a strange instrument. With a view to the introduction of uniformity a conference on the subject was arranged by the College of Organists in London, and a series of resolutions and a series of recommendations were published which deserve attention (1881), though they have now been withdrawn. We may mention that the parallel concave form was recommended for the pedal board, and 2 in. for the scale. The positions of the stops of the various organs were to be as follows:—

The order of compositions, &c., from piano to forte was to be in all cases from left to right. The groups of compositions were to be in the order from left to right—pedal, swell, couplers, great.

14.—Relative Position of Manual and Pedal.

Two other points of detail may be alluded to. One is the position of the pedal board with reference to the keys. The height from the

middle of the pedals to the great organ keys, it is agreed, should be 32 in. But as to the forward position there is a difference. The resolutions said that “a plumb-line dropped from the front of the great organ sharp keys falls 2 in. nearer the player than the front of the centre short key of the pedal board.” The old arrangement gave usually 1 in. for this distance. But it is thought that the change has not gone far enough, and 4 in. has been found preferable. There is scarcely any single arrangement which is so important for the comfort of the player as having sufficient space in this direction (fig. 14). The second matter is the provision of some other means of acting on the swell than by the swell pedal. The use of the swell pedal is inconsistent with the proper use of both feet on the pedal keys; and there is no doubt that incorrect habits in this respect are commonly the result of the English use of the swell pedal. In fact, players sometimes keep one foot on the swell pedal all the time, so that proper pedal playing is impossible. Arrangements have been devised by means of which a movable back to the seat can be made the means of acting on the swell. The first “recommendation” of the College of Organists illustrated the requirement; it was, that “the consideration of organ-builders be directed to the widely-expressed desire for some means of operating on the swell in addition to the ordinary swell pedal.” G. Cooper had a movable back to the seat of the organ at St Sepulchre’s, London. The swell was opened by leaning back, so that it could only be used when the swell was coupled to the great. The writer has had an organ for more than twenty years in which the movable back is provided with a strap passing over one shoulder and buckling in front. It opens the swell when the player leans forward. It is most valuable, particularly in such things as accompanying the service. The emphasis required is obtained when wanted without taking the feet from their other duties. Young people pick it up easily; older people have difficulty.

As an example of an organ of a complete but not enormously large character, we give the details of the organ at St George’s Chapel, Windsor, which was rebuilt by Messrs Gray and Davidson, according to Sir Walter Parratt’s designs, in the year 1883.