19,697. Cameron, D., Commin, F. J., and Martin, A. J. Sept. 16. Sewage filters; filter beds; supplying and discharging liquid.- Relates to apparatus, of the kind described in Specifications No. 3003, A.D. 1896, No. 27,349, A.D. 1897, and No. 5671, A.D. 1898, for regulating the flow of sewage, sewage effluents, or other liquids to or from filter beds, tanks, or other receptacles. Fig. 1 shows an arrangement of the kind described in Specification No. 5671, A.D. 1898, for use with two filter beds. The buckets 3, 4 are fixed to rods 9, 10, connected to an oscillating lever 8 and to discharge valves 6. 7, fitted within the discharge wells 1, 2. into which the sewage &c. flows from the filter beds, as described in Specification No. 5671, A.D. 1898. The buckets are alternately filled and discharged, so as to actuate the valves 6, 7, by means of a siphon 5, which may have upturned extremities. In a modified form, for use with two filter beds, the discharge and supply valves may be connected to levers mounted upon an oscillating shaft, but the rods of the supply valves may have looped ends which are capahle of sliding over pins on the ends of the levers supporting the valve rods. By this means the discharge valves are opened gradually, and; in order still further to regulate the discharge, the discharge valves may be made of suitable conical or other form. Fig. 4 shows an arrangement for discharging sewage &c. from a tank 19 into filter beds 23, 24 alternately. An oscillating shaft 11 is mounted between the filter beds, and carries a tipping-trough 20, and a frame supporting two buckets 3, 4. The sewage &c. is discharged by two siphons 17, 18, acting alternately, into the trough 20, and thence into troughs 21, 22, situated above the beds 23, 24 respectively. The flow of liquid through the siphon 17 or 18 is stopped as soon as the corresponding filter bed is full, by means of air valves 27, actuated by rods 29 connected to the trough 20. The shaft 11 may be actuated by means of the buckets 3, 4, which receive the overflow from the filters, or it may be actuated in any other manner In a modification of this arrangement, the sewage &c. flows along a siphon into a chamber provided with two discharge valves, which are operated alternately so as to allow the liquid to flow into the filter beds. Fig. 8 shows another modification, by which the sewage &c. is introduced from a tank 19 to the filter beds. A discharge valve 37 is actuated intermittently by a rocking lever 36, which is connected to a tipping- trough 34 supplied with liquid from an overflow pipe 35. When the valve 37 has been raised, the liquid flows to one of two filter beds, the flow being controlled, preferably, by valves actuated by means of a shaft 11 which carries a frame 12 and buckets 3, 4, supplied with liquid from pipes 25, 26, connected to the discharge wells of the filter beds. During the filling of a filter, the trough 34 is held in its tipped position by a bell-crank iever 39 actuated by an arm 38 on the shaft 11. In Specification No. 5671, A.D. 1898, a chamber is described in which the bucket actuating the valves is suspended. In order to prevent this bucket from descending too rapidly, water or other liquid is retained in the chamber for the purpose of partially supporting the bucket in its descent. In connection with this modification of the invention described in Specification No. 5671, A.D 1898, a reference to Specification No. 27,349, A.D. 1897, is made. Fig. 11 shows an arrangement for controlling the flow of sewage &c. from one filter bed or tank to another. Sewage &c. is admitted to an upper filter bed 23 from a pipe 21 provided with a valve 9, which is connected to a rocking lever 8 actuated by means of a bucket 3. The lever 8 also supports a discharge valve 6, which is closed when the valve 9 is open and vice versÔ. The sewage &c. passes from the filter bed 23, past the valve 6, to a lower bed 24, which is provided with a discharge valve 7 actuated by means of a rocking lever 43 and bucket 4. The bucket 3 is supplied with liquid from the discharge well 1, by means of a pipe 25, four-way cock 41, and pipe 42 ; the bucket 4 may be supplied from any suitable source. The bucket 4 is emptied periodically by means of a siphon 48 connected to the discharge well 2, and, when emptied, the bucket is held in its lowest position by a rod 52 connected to the lever 43, and to a catch 49 actuated by a cam or projecting piece 50 attached to the rod of the bucket 3. A series of pairs of such filters may be used, and the overflow from the filter 23 may be led to any other pair by means of the cock 41 and suitable pipes arranged in a way similar to that described in Specification No. 3003, A.D. 1896. In a modified form, the valves of the upper and lower filters may be actuated bv a single set of rods attached to a rocking shaft. The sewage &c. may be aÙrated as it leaves the filter beds ; for this purpose the discharge pipes may be perforated, or provided with pipes for conducting induced currents of air into the liquid.