At Far Rockaway, L. I., the water is lifted from wells by a Worthington Pump, and is discharged over the bell of a vertical 16-inch pipe, from which it falls through the air to the water in a receiving chamber around it. The simple fall through the air aerates the water sufficiently. From the receiving-chamber the water is taken to either or both of two filters, each with an area of 20,000 square feet. These filters are open, with brick walls and concrete bottoms, three feet of sand and one foot of gravel, and the underdrains are of the usual type. The water flows through regulator-chambers to a well 25 feet in diameter and 12 feet deep, from which it is pumped to a stand-pipe in the town. The plant was built to treat easily three million gallons per day, and has occasionally treated a larger quantity. Either filter yields the whole supply while the other is being cleaned. The rate of filtration in this case was made lower than would have otherwise been necessary, as there was an alternate supply, namely, the water from two brooks, which could be used on occasions, and to purify which a lower rate of filtration was regarded necessary, than would have been required for the well-water. The removal of iron is complete. [Illustration: FIG. 25.] The plant of the Rumson Improvement Company at Red Bank, N. J., is quite similar to that at Far Rockaway, but is much smaller. The outlet is a 6-inch pipe perforated with 1/4-inch holes which throws the water out in a pine-tree shape to the receiving-tank, thoroughly aerating it. Each of the two filters has 770 square feet of area. The filtering material is three feet of beach sand. From the regulator-chamber the water flows to a circular well 18 feet in diameter, covered by a brick dome and holding 17,000 gallons, from which it is pumped to the stand-pipe. Either of the filters will treat ten thousand gallons of water per hour, which is equal to the capacity of the pumps; and as the consumption is considerably less than this figure, they are only in use for a part of each day, the number of hours depending upon the consumption. These filters are shown by the accompanying plan. The cost of the work was as follows: Filters and pure-water reservoir, with piping and drains complete $3,799.47 New pump and connections 492.68 Engineering and superintendence 992.91 --------- Total cost of plant $5,285.06 The engineer who operates the pumps takes care of the filters, and no additional labor has been required. The entire cost of operation is thus represented by the additional coal required for the preliminary lift from the wells to the filters. The effluent is always free from iron.