A 1" lead waste-pipe was connected with the soil-pipe just above the basement floor. This branch waste had a number of ventilating openings made upon it, and a deep-seal S-trap at its end. The trap had three ventilating openings in its outlet arm, one at the crown, and the others below the crown as shown. All the vent openings both on the trap and on the branch waste were provided with small connecting tubes so arranged that the rubber ventilating flue could be readily attached to either. The openings were, furthermore, all provided with closely fitting corks, so that they could be hermetically sealed. By this arrangement the effect of ventilation at different points of the trap or its waste-pipe upon its water-seal could be accurately tested. Further tests on evaporation were made by connecting a second branch waste below the first with a brick flue heated by a stove.

Figs. 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12, show various traps tested in these experiments. Other traps were tested at the same time with these at the request of the manufacturers. Still others were sent us on the invitation of your Board; but as none of these traps except those shown, were able to preserve their seal against the tests applied, and as most of them have already been tested in the experiments for the National Board of Health, and the tests published, by which their power of resistance as relates to that of a ventilated S and to a pot-trap was made known, it has been thought unnecessary to publish the results obtained in these experiments. The records on any of these traps will, however, be cheerfully sent to its proprietor upon his request. Our tests fall under three general divisions: (I) Siphonage; (II) Back-Pressure; (III) Evaporation.

The Siphonage And Evaporation Of Traps Report To T 592

Fig. 2 (556).

The Siphonage And Evaporation Of Traps Report To T 593

Fig. 3 (557).

The Siphonage And Evaporation Of Traps Report To T 594

Fig. 4 (558).

The Siphonage And Evaporation Of Traps Report To T 595

Fig. 5 (559).

The Siphonage And Evaporation Of Traps Report To T 596

Fig. 6 (560).

I. Experiments on Siphonage.

These experiments are subdivided into (A) those on ventilated S-traps; and (B) those on pot and other traps, unventilated. Except where otherwise specified, the tests were made at the outlet on the second floor, at a distance of about 11' below the bottom of the water-closet trap, since at this point the siphonage proved to be most severe.

The Siphonage And Evaporation Of Traps Report To T 597

Fig. 7 (561).

The Siphonage And Evaporation Of Traps Report To T 598

Fig. 8 (562).

(A) Experiments on Ventilated S-Traps. These experiments are again divided into: - (1) Those in which the siphonic action was produced by a trapped plunger-closet, with and without the combination of a bath-tub.

(2) Those in which a trapless plunger-closet was used.

(1) Experiments on the Siphonage of Ventilated S-Traps by a Trapped Plunger Water-closet.

The tests were made first with the water-closet alone.

(a) An unventilated S-trap was, of course, completely siphoned out by a single discharge of the closet.

(b) A 1" ordinary cast-lead S-trap, having a 1" vent-hole at the crown, and a 1" pipe of smooth clean lead 17' long attached at the opening was then tested. Three discharges of the closet were sufficient to break the seal. The experiment was repeated several times with the same result. (c) A I 1" cast-lead S-trap, constructed as shown in Figure 13, was tested. The vent opening at the crown was 1" in diameter; the others were 1" in diameter.

The Siphonage And Evaporation Of Traps Report To T 599

Fig. 9 (563).

The Siphonage And Evaporation Of Traps Report To T 600

Fig. 10 (564).

The Siphonage And Evaporation Of Traps Report To T 601

Fig. 11 (565).

The Siphonage And Evaporation Of Traps Report To T 602

Fig. 12 (566).

The Siphonage And Evaporation Of Traps Report To T 603

Fig. 13 (567).

A 1" pipe 7' long was attached to the vent opening at the crown, the others being closed. Five discharges of the closet sufficed to break the seal.

The pipe was increased to 17'. The seal was then broken by four discharges.

This opening was then closed and the long pipe was attached to the middle vent. The first discharge of the closet lowered the seal 1". The second broke the seal.

The lower vent was then tested with the same pipe, 17' long. Four discharges were required to break the seal.

(d) The effect of the discharge of the water-closet while the bath-tub was emptying was then observed.

An ordinary 1" S-trap was first tested. With a vent opening the full size with the bore of the trap, but without vent-pipe, a single discharge of the water-closet and bathtub together lowered the seal 1/8". A second discharge failed to lower the water any further.