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only a very limited supply of even well and cistern water. From their method of construction, however, as has been shown, every portion of the system is capable of being, and actually is, inspected periodically. Every length of pipe can be examined and cleaned, not only by flushing, but by scrubbing with wire brushes.

When it is desired to flush any line of pipe, a sand bag is used as a plug for the outlet of a manhole, which is then filled with salt water by the town water-cart,-rather a primitive fashion of procedure, but one that it was decided to adopt, temporarily, during the first season, or until it should be demonstrated by actual experiment where flush tanks should be located and what their size should be. As a rule, water enough is put into the manhole in question to make a solid water plug, as it were, for forty feet of the sewer, below the manhole.

The flushing by this crude method has been so successful, and has to be attended to so seldom, that it is quite possible the special flush tanks may be omitted entirely.

During construction, silt, in the form of fine sand and clay, found its way into some of the pipes, and upon completion of the work deposits were found in certain sections; in one case to a depth of over three inches, and very compact. The question of removal seemed quite a serious one; the more so, after repeated flushings had failed to carry off the obstruction.

After repeated experiment one of the two following courses was adopted in every case: a shingle with a lighted candle fastened upon it (see Fig. 4) was allowed to float down the pipe from a manhole, being controlled from the initial point by a string, so that it could be stopped when desired. An obstruction met could be located by measuring the length of the string. This being ascertained, a hoe or rake (see Fig. 5) was introduced on one end of a series of jointed rods (which when screwed together somewhat resemble a fishing pole), and the sand loosened and afterwards flushed off with water; or, a stout twine was attached to a wooden plug, which was floated down from one manhole to another, and to which, in turn, was fastened a small rope and a section of rather heavy iron chain, which latter could

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be dragged to and fro, until the whole mass of sediment was loosened.

These appliances, except the shingle and candle, are the ones ordinarily in use for pipe sewers, and were found tolerably satisfactory, though not wholly so. To meet the want still felt, circular brushes of various sizes that could be attached to a rope or a rod and then pulled or pushed through, were devised; at first, these were made of stiff bristles, but now are constructed of flat steel wires, fastened to a wooden core (see Fig. 6), and with the arrangements before mentioned appear to be sufficient for all purposes. After being once thoroughly cleaned, the question of keeping the sewers in that condition was much simplified.

Inspection now consists either in reflecting the sunlight through the sewer, from one manhole to another, by means of mirrors (see Fig. 7), which enable a very fair inspection without any flush whatever, or in the use of the shingle and candle before mentioned. If any foreign matter appears to be in the pipe, its position can be located (if the day be sunny) by counting the joints in the pipe, which can be seen by the mirrors above referred to, and the brush, chain, hoe or rake used, as may seem best.

The system, which is to-day nearly five miles in length, is intended to be thoroughly ventilated, and includes not only the public sewers, but all private drains below running traps.

The lower manhole on each trunk sewer is provided with a perforated cover, to relieve the other portions of the sewer from the pressure caused by heavy surf, and not, as has been suggested, as a fresh-air inlet, for, on the upper side of each manhole, is a flap valve or tide gate which would effectually prevent any such use being made of the perforated cover. The sewers and house connections above the last manhole on each trunk line (which manhole is intended for the purpose above described) are water-tight, so far as careful work can make them. House connections are entered in 4-inch Y pipes, and the ventilation for both sewer and house drain is provided for by a 4-inch pipe, connecting outside each and every house, extending from the main drain of each building just below the running trap, to some point above

Section of Manhole, showing method of inspection with mirror:

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