When fresh water is admitted to the swimming bath, the dirty water, overflowing from the opposite end through pipe U, Fig. 5, may be discharged through sewer pipe V, but is generally taken through the suction pipe W of pump J, Fig. 6, which delivers it through pipe A to the Jewett gravity filter B, whence it is drawn through suction pipe C of pump K, and delivered through pipe D to the bath heater H, Figs. 3 and 5. When the water in the filter rises to a fixed height, the heavy float E, suspended by chain F, attached to the counterweighted lever G, opens the valve H, and admits steam from branch I of main V to the pump K which works until it reduces the level of the water in B and the descending float cuts off the steam and stops the pump. The pump may also be operated by the hand valve W. L is a steam pipe to pump J. and M M are exhaust pipes. N and O are overflow pipes discharging into the sewer. Ordinarily valve P is closed, but it may be opened to drain pipes V and I through pipe C into N. R R are delivery pipes to the boiler feed pipe. S is a hose connection T T are suctions direct from the city water supply and U is a connection to the delivery pipe of the feed pump. Thus these two pumps, J and K, the roof tank pump N, Fig. 5, and the boiler feed pump (not here shown) are interchangeable throughout, and each can be connected on to the system of any of the others. When it is necessary to wash the filter, pump J forces city water from pipe T through pipe C and it passes through the filter in the reverse direction, and thus escapes into the sewer pipes.

Figure 7 shows the construction of filter B, Fig. 6, but represents the well to be made of hooped wooden staves instead of steel plates, as is really the case.

About half of the upper part of the filter and the front wall of the remainder is removed so as to show the washing and collecting apparatus in the filter chamber from which the filtering medium is shown removed. The hand wheel W, through pinion G, shaft S, and beveled gear B, drives shaft A, revolving its horizontal arms D D, which carry cutting bars E E, which, when the filter is washed, disintegrate the filter bed. On the bottom of the filter a cast-iron collecting box H has connected to it numerous lateral pipes with horizontal inlets, through which the water is received and delivered to the supply main at C. Mr. P. Lauritzen was the architect of the club-house, and the plumbing was executed by Byrne & Tucker, all of New York City.