of 5.6 feet. The flushtank is placed at this point, receiving the entire flow from the sewer above, retaining it until full, and then discharging the whole mass in such volume and with such head as to ensure the production of a cleansing flow through the siphon, the construction of which is as follows:

It was necessary to lay the siphon at one side of the bridge on account of the mud sills interfering with its bedding if placed under the bridge. Piles four inches square were driven opposite each bent of the bridge and capped and supported. A temporary platform was built at the water level to work from, both in excavating the bottom and in leading the joints. The pipe was supported from timbers six inches square placed on top of the cap pieces. There was quite a strong current, and guides were driven at every other joint to prevent the pipe swinging out of line in lowering. The excavation was mostly sand. Clay was encountered in two places. A few small stones were encountered but these were easily removed with rakes. After the bottom was excavated, the lower staging was removed. Men were placed at the supporting ropes at each joint; a mark was made on each rope one foot from the timber, and every line was slacked off as uniformly as possible and held at the mark. This operation was repeated until the pipe rested on the bottom. The accompanying illustration shows the pipe swung, ready for lowering. Figure 1.

Another difficulty consisted in the fact that as the lower portion of the Winnipesaukee river and the adjoining bay of the lake into which it discharges are so much used for pleasure boating ("The Laconia Navy"), it was entirely inadmissible to discharge sewage at the shore. Both outlets are carried to the deep channel where the river flows into the lake, through iron pipes, that on the east side being twelve inches in diameter and one hundred and thirty-five feet long, and that on the west side being fourteen inches in diameter and three hundred and thirty-one feet long. These pipes are laid in the sand from the shore to about the point of discharge. The placing of the fourteen-inch outlet (Water street) is

shown in figures 2 and 3. The trench was close sheeted and it was found necessary in places to drive a board outside in order to cover the joint. Pieces of bagging were also used for the same purpose. The water was not pumped out at all but the sand was so fine in places that it ran through the smallest opening. One set of rangers was placed at the water line and the sheeting was driven about a foot below the bottom of the trench. This held it in place perfectly. The last three lengths of pipe were laid on a platform which was lowered to a pile support at its outer end. The pipe was supported in the same manner as at the other outlet and at the bridge. It was lowered nearly to the rangers at the surface of the water. These rangers were then taken out and placed above the pipe. The pipe was then lowered to grade and enough sand thrown in to bed it. The sheeting was then drawn.

Except for these peculiarities and for the use of "inspection pipes," to be described below, the system is substantially the same as that at Keene. It comprises 10.28 miles of sewers, all of pipes ranging in diameter from six inches to fifteen inches, 65 per cent of the whole being six-inch. There are forty-five flushtanks, thirty-one manholes, and eighty-two inspection pipes. The work is not yet entirely completed and exact figures cannot be given, but the amount paid under the contract will be not far from $54,000.

The work was begun July 7, 1891 and was practically completed by November 20, 1891. It was all carried out under the engineering control of Waring, Chapman & Farquhar of Newport, R. I., my partner, Mr. Chapman, being the engineer in charge.

The inspection pipes referred to above are an improvement added since the work at Keene was done. They take, very largely, the place of manholes and are placed at intervals of about two hundred to three hundred feet, average. They consist of an iron pot or chamber built at the surface of the street with an iron cover, all being strong enough to stand the concussion of traffic. This chamber which is about