Playing on the old instruments was fatiguing and uncomfortable. The touch was heavy and, when one used both the pedals and the keyboards, a real display of strength was necessary. A similar display was necessary to draw out or push back the registers, some of which were beyond the player's reach. In short, an assistant was necessary, in fact several assistants in playing large organs like those at Harlem or Arnheim in Holland. It was almost impossible to modify the combinations of stops. All nuances, save the abrupt change from strong to soft and vice versa, were impossible. It remained for Cavaille-Coll to change all this and open up new fields of usefulness for the organ. He introduced in France keyboards worthy of the name, and he gave to the higher notes, through his invention of harmonic stops, a brilliancy they had lacked. He invented wonderful combinations which allow the organist to change his combinations and to vary the tone, without the aid of an assistant and without leaving the keyboard. Even before his day a scheme had been devised of enclosing certain stops in a box protected by shutters which a pedal opened and closed at will; this permitted the finest shadings. By different processes the touch of the organ was made as delicate as that of the piano. For some years the Swiss organ-makers have been inventing new facilities which make the organist a sort of magician. The manifold resources of the marvellous instrument are at his command, obedient to his slightest wish. These resources are prodigious. The compass of the organ far surpasses that of all the instruments of the orchestra. The violin notes alone reach the same height, but with little carrying power. As for the lower tones, there is no competitor of the thirty-two-foot pipes, which go two octaves below the violoncello's low C. Between the _pianissimo_ which almost reaches the limit where sound ceases and silence begins, down to a range of formidable and terrifying power, every degree of intensity can be obtained from this magical instrument. The variety of its timbre is broad. There are flute stops of various kinds; tonal stops that approximate the timbre of stringed instruments; stops for effecting changes in which each note, formed from several pipes, bring out simultaneously its fundamental and harmonic sounds; stops which serve to imitate the instruments of the orchestra, such as the trumpet, the clarinet, and the cremona (an obsolete instrument with a timbre peculiar to itself) and the bassoon. There are celestial voices of several kinds, produced by combinations of two simultaneous stops which are not tuned in perfect unison. Then we have the famous _Vox Humana_, a favorite with the public, which is alluring even though it is tremulous and nasal, and we have the innumerable combinations of all these different stops, with the gradations that may be obtained through indefinite commingling of the tones of this marvellous palette.