��3. It was naturally a source of considerable pleasure to an organist to have the advantage of couplers to unite from above and below, and from the right and left, to improve the effect of his performance ; but this happy state of feeling was apt to be qualified by the reflection that in consequence of the demand upon the wind, and the greatly increased rapidity with which it had to be supplied, there was just the possibility of his being required at some time to attend an inquest on a dead blower, and of his being pronounced to have contributed materially to the demise of the unfortunate man. Hence the invention of some mechanical means for blowing the bellows, and for increasing or decreasing the speed of the supply, according as much or little might be required, became a matter of some concern and much importance.
The first piece of mechanism devised for this purpose was the 'Hydraulic Engine' of Joy and Holt, afterwards David Joy, of Middlesborough. This consists of a cylinder similar to that of an ordinary steam-engine, but deriving its motion from the pressure of a column of water, admitted alternately to the top and bottom of the piston. Engines of this kind are attached to the organs at the Town Hall, Leeds; the parish church, Leeds; Rochester Cathedral ; the Temple Church, etc., etc.
The ' Liverpool Water Meter,' as patented by the late Mr. Thomas Duncan, and made by Messrs. Forrester & Co., of Liverpool, consists of two cylinders, with pistons and slotted piston- rods working a short crank -shaft. There is an engine of this kind, also, at the Temple Church.
Gas Engines are also used for blowing organs. There is a large one in daily operation at York Cathedral, another at Salisbury Cathedral, and another at the Normal College for the Blind, Upper Norwood.
Among the most notable organs recently erected by English organ-builders maybe mentioned those in St. Paul's Cathedral, Albert Hall, and Alex- andra Palace, by Willis ; in Christ Church, West- minster Road, Newington parish church, and St. Peter's, Eaton Square, by Lewis & Co. ; in the City Temple, and the Temple Church (rebuilt), by Forster & Andrews ; in the Cathedrals at Man- chester and Worcester, and at St. Andrew's Hoi- born, by Mr. T. Hill ; at the Oratory, Brompton, by Messrs. Bishop & Starr ; at St. Peter's Church, Manchester, by Messrs. Jardine & Co. ; at ' The Hall,' Regent's Park, by Messrs. Bryceson & Co. ; and in St. Pancras Church, and St. Lawrence Jewry, by Gray & Davison ; etc., etc.
The eminent French builders, Cavaille'-Coll & Co. have erected some favourable examples of their work in the Town Halls of Manchester and Sheffield, etc. ; while the excellent firm of Schulze & Co has constructed fine organs in the parish church at Doncaster and at St. Mary's, South Shields. This account would be incom- plete were we to omit to mention that Messrs. E. & G. Hook, and Jardine & Son, of New York, and others, have enriched a vast number of the churches and other buildings in America with fine modern specimens of organs of their con-
str action ; and that a very fine example by Messrs. Walcker & Son, of Ludwigsburg, was imported in 1863, and erected in the Boston Music Hall, United States, where it gave an impetus to the art in that enterprising country.
The following works have been consulted in the preparation of this article.
Prsetorius, 'Theatrum instrumentorum.' Wolfenbtlttel, 1620. J. Schmid, 'L'Orgue d'Aloyse Mooser.' Fribourg, 1840. Schlimbach, 'Die Orgel." Leipzig, 1843. Seidel, ' Die Orgel und ihr Bau.' Breslau, 1843.' Beschrijving der groote Orgel in St. Bavo-Kerk te Haarlem.' Haarlem, 1845. ' Orgue de 1'eglise royale de St^ Denis, construit
H. Jimmerthal, 'Die grosse Orgel in der St. Marien- Kirche zu Lubeck.' Erfurt und Leipzig, 1859. E. J. Hop- kins, and E. F. Kimbault, 'The Organ, its history and construction.' London, Cocks & Co., 1877. Otto Wange- mann, 'Geschichte der Orgel und der Orgelbaukunst. Demmin, 1879. [E. J. H.]
ORGAN-PART. The music of the part to be played by the organist in an oratorio, psalm, cantata, or other sacred work. Formerly the organist sat at performance with the score before him ; and from the figures attached to the bass line, with the assistance of such directions as Organo, Senza organo, Tasto solo, Unisono, etc., he con- structed the organ accompaniment according to his ability ; and in the case of airs it required the special training of that contrapuntal age to do it properly. Nowadays less reliance is put on the casual ability of a performer, and the com- poser writes out the organ-part as completely as he does that for the violin, harp, or oboe. St. Paul, the Lobgesang, and Elijah, have each their published organ-part. Mendelssohn also wrote organ-parts for Handel's Solomon and Is* rael in Egypt the latter in his edition of Israel for the London 'Handel Society' grounded on the figured-bass of the composer. [G.]
ORGANO denotes the organ part in a score. ORGANO PIENO means Full organ that is, the entire power of the instrument. [E.J.H.]
ORGANUM (equivalent to Diaphonia ; and, though less exactly, to Discantus). It is impos- sible to ascertain the date at which Plain Chaunt was first harmonised; and equally so, to discover the name of the Musician who first sang it in harmony. We know, however, that the primi- tive and miserably imperfect Counterpoint with which it was first accompanied was called Or- ganum ; and we have irrefragable proof that this Organum was known at least as early as 880 ; for Scotus Erigena, who died about that date, speaks of it in his treatise ' De divina- natura,' in such terms as to leave no doubt as to its identity, and to show clearly that it waa sufficiently well understood at the time he wrote to serve as a familiar illustration. 1
No mediaeval writer has given us the slightest hint as to the etymology of the word ; but most modern historians are agreed that the prima facie derivation is, in all probability, the true one. When Organs were first introduced into tlie Ser- vices of the Church probably in the ;th century, but certainly not later than the middle of the
l 'Ut enim organicum melos ex dlversls qualitatibus et quantiU- tlbua conficltur,' etc.