board. There are drawings of that period extant, which represent the organ as an instrument having but few pipes, blown by two or three persons, and usually performed on by a monk. The keys, which were played upon by hard blows of the fist, were very clumsy, and from four to six inches broad. About the end of the eleventh century semitones were introduced into the keyboard, 
Fig. 1.—Antique Sculpture in the Museum of Arles, dated XX.M.VIII, representing organ blown by the mouth. but to all appearances its compass did not extend beyond three octaves. The introduction of pedals, in 1490, by Bernhardt—giving a compass B flat to A—was another important contribution to the instrument. These were merely small pieces of wood operated by the toe of the player.
Jordan's "swell organ," which was introduced about 1712, in England, is deservedly ranked as one of the greatest advances in organ-building known up to that year. Jordan was renowned among the builders of his century. Green, another noted English builder of the period, improved the swell and added a score of lesser innovations which give him a prominent place in histories of the instrument. Milton was cheered and consoled in his blindness, as we learn from his biographers, by a portable organ. This was a form of instrument called the regale, which was in use during the sixteenth and seventeenth centuries. It has, however, been obsolete for over a century.
From being a mere accessory to church choral services, the organ has been improved in time by the introduction of stops, 
Fig. 2.—Representation of an Organ on an Obelisk at Constantinople, erected in the fourth century. instrumental effects, and the extension of pedal and manual compass, until it has attained such a recognized position as a solo instrument that it might now be called an orchestra in itself. In the last century the men notably associated as builders with its progress were Jordan, Green, Schroder, Siberian, Seltzer, Harris's, Avery, By well, and Father Schmidt. Fresco, the organist, who wrote the first fugues and musical compositions according to the highest capacities of the organ in his lifetime (1580-1640), gave the development of the instrument a great impetus. Treadwell, J. S. Bach, Handel, and Albrecht followed as executants and composers of organ
