21,885. Taylor, J. Oct. 11. Strainers. -Relates to apparatus for moistening air in mills, weaving-sheds, factories, &c., and consists of means for cleansing strainers in the water-supply pipes. In each of several forms both of automatic and hand-operated devices, the strainers are cleansed by a reversal of the direction of the flow through them when a predetermined pressure is reached in the supply pipe, such reversal generally taking place at the starting and stopping of the water supply. In the automatic device shown in Figs. 1 and 2, a cylindrical strainer K is mounted within a casing A, and encloses a looselyfitting piston having an upper portion comprising a hollow plunger H terminating in a conical valve G seating against a port in the supply pipe C ; the lower part of the piston forms a valve F adapted to seat on a ring b, and receives the stem of a spring-pressed piston working in a dash-pot R. When the water supply is started, the valve G is unseated, and the pressure, acting on an increased area, forces the plunger steadily downwards, water passing through ports I, J and outwards through the strainer, carrying away fluff, dirt, &c. through ports a to a waste-outlet pipe U. The cleansing action continues until the valve F is seated and the ports J fall below the strainer ; the normal working condition is then attained, water passing inwards through the strainer and by a passage W to the humidifier Z. The casing is made in several parts connected by joint rings B. The cleansing action when the supply is stopped, which is similar to that at starting, is expedited by providing an air vessel, or an auxiliary cylinder furnished with a spring-pressed piston, to facilitate the reversal of the flow. In another automatic device, the water passes first through an auxiliary chamber, raising a spring-controlled lift admission valve therein, before acting upon a spring-pressed hollow plunger having a closely-fitting piston head. Another device is adapted for use with a plate form of strainer. Fig. 10 shows a hand-operated device in which the reversal of flow through the strainer K is effected by means of a tapered multiple-way plug-cock, which is provided with bores communicating with a ported chamber w<2> within the strainer, and with other bores communicating respectively with passages leading to the outside of the strainer, the waste-water outlet, and the humidifier. In a modification, the ported chamber w<2> is separate from the plug-cock, which consists of an ordinary four-way cock arranged in a conduit below the strainer. In the form shown in Fig. 9, the water flows normally through a bye-pass z<2>, passing inwards through the strainer to the humidifier pipe D ; whenever the pressure in the chamber U<2> is reduced by the opening of the waste-water outlet at the cock e, the plunger J is moved downwards, and a reversal of flow occurs. In another form, the reversal of flow is effected by the operation of a hollow plunger by means of a ring handle attached to its projecting stem.