When Willis built the great organ in St. George's Hall, Liverpool, in 1855, he installed an eight-horsepower steam engine to provide the wind supply. There is a six-horse steam engine in use in Chester Cathedral (installed 1876). Gas and petrol (gasoline) engines have been used extensively in England, providing a cheaper, but, with feeders, a less controllable, prime mover. By far the commonest source of power has been the water motor, as it was economical and readily governed, and as water pressure was generally available, but the decline of the old-time bellows, with the fact that many cities to-day refuse to permit motors to be operated from the water mains, have given the field practically to the electric motor, now generally used in connection with some form of rotary fans. The principle of fans in series, first introduced by Cousans, of Lincoln, England, under the name of the Kinetic Blower, is now accepted as standard. This consists of a number of cleverly designed fans mounted in series on one shaft, the first delivering air to the second at, say, 3-inch pressure, to be raised another step and delivered to the next in series, etc., etc. This plan permits tapping off desired amounts of air at intermediate pressures with marked economy, and as it is slow speed, and generally direct connected with its motor on the same shaft, it is both quiet and mechanically efficient. [1] One object of this was to prevent what was called "robbing." While the pressure of the wind might be ample and steady enough with only a few stops drawn, it was found that when all the stops were drawn the large pipes "robbed" their smaller neighbors of their due supply of wind, causing them to sound flat. By giving each pipe a pallet or valve to itself, the waste of wind in the large grooves was prevented. Another object was to get rid of the long wooden slides, which in dry weather were apt to shrink and cause leakage, and in damp weather to swell and stick. [2] A striking instance of the difference between the two kinds of pallet can be seen in All Angels' Church, New York. The organ was built originally by Roosevelt, with two manuals and his patent wind-chest. In 1890 the church was enlarged and Jardine removed the organ to a chamber some thirty feet above the floor and fitted his electric action to the Roosevelt wind-chest. At the same time he erected an entirely new Choir organ, in the clerestory, with his electric action fitted to long pallets. The superiority of attack and promptness of speech, especially of the lower notes, of the Choir over the Great and Swell organs is marvelous. The same thing can be seen at St. James' Church, New York, where the Roosevelt organ was rebuilt with additions by the Hope-Jones Organ Co. in 1908. [3] Some congregations could not stand them and had them taken out. [4] Wedgwood: "Dictionary of Organ Stops," p. 167. CHAPTER IX. TRANSFERENCE OF STOPS.