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twenty inches in diameter has two oblique arms, set at an angle of forty-five degrees and pointing, one up stream and one down stream. The openings into these arms are closed by cast iron doors, held fast by an iron bar between them which is fastened in place with a Yale lock. The arms are long enough to enter the collars of eight-inch pipe, which rise obliquely toward them from the top of the sewer. The lowest pipe of this oblique connection, on six-inch sewers, reduces in size from eight-inch to six-inch and enters the branch of the sewer. By removing the cover, releasing the bar, and uncovering the arms, a straight line of sight is given into the sewer so that by throwing down the light from a bull's-eye lantern, the condition and character of the flow can be perfectly inspected.

The details of these appliances are shown in the accompanying cuts. Figures 4 and 5.

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Cords can be floated from the down-stream arm of one chamber to the up-stream arm of the next below, by which ropes may be drawn through, carrying steel brushes, or whatever other appliances may be used in cleansing. When sewers are to be cleansed by passing balls through them slightly smaller than their interior diameter, so as to produce a cleansing current as the sewage flows around the ball, a strong cord is attached to the ball by which it is kept under control until it shows itself at the inspection pipe below, where it may be pulled up, or it may be drawn back to the starting point.

In case of stoppage, the sewer may be easily plugged, through the down-stream branch of the inspection pipe next below, and then filled with a solid column of water, which being churned with a plunger from the up-stream pipe, produces a direct movement on the obstruction and sets it free. These pipes have the advantage that they make it possible to do all cleansing work from the surface of the street instead of working in the contracted quarters at the bottom of a manhole. As their openings are locked fast, one of the most serious objections to manholes, the opportunity offered for malicious persons to throw in obstructions, is obviated.

Some difficulty was caused in construction by the uncertainty as to the location of water pipes. "These were laid in the centre, at one side, or diagonally across the streets as the case might be. No record of their location was kept, and a margin of five feet from where the pipes were supposed to be, proved to be none too much.

The material used for these sewers was granite pipe, manufactured by Knowles, Taylor & Anderson of East Liverpool, Ohio. It was very satisfactory save that a considerable amount of the smaller sizes had to be rejected because it was not straight. "The bells were especially large and there was not a single pipe that required chipping." This is a great recommendation.

The joints of the pipes were inspected and carefully covered before the cement had set. Damage to be caused by jarring the pipe and cracking set cement was thus avoided.

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