Until the middle of the nineteenth century little interest was taken in organ-building in America. The erection of the great organ in the Music hall, Boston, by a German builder, Walcker, of Wurtemberg, gave the first impetus to public interest in the matter. There are now several good organ-makers, and one of them, Roosevelt, has invented "the automatic adjustable combination," which enables the player to place any required combination of stops under immediate control, and to alter such combinations as frequently as desired. By his construction of the wind-chest, also, each pipe has its own valve, actuated by compressed air. Among the largest organs in America are the organ of the Catholic cathedral, Montreal, of the cathedral of the Holy Cross, Boston, which possesses eighty-three stops; the Music Hall, Cincinnati, with ninety-six stops and four manuals, and the Tremont Temple, Boston, with sixty-five stops.