10. The foregoing experiments prove that soil-pipes, like waste-pipes, must have their branches ventilated to prevent loss of water-seal in the traps fixed upon them. They also D E F A B prove that when more than one 11. To ventilate the branches or traps, as shown in fig. 95, is not ventilating the traps according to their needs, though, unfortunately, in practice they are often so treated. With such a method, during the time a discharge is passing through the main pipe, i.e., when the ventilation is most needed for the preservation of the seals of the traps, all ventilation is cut off from the traps below the place of the discharge; e.g., a discharge sent through the upper trap, A, fig. 95, would often pass through the main pipe-waste-pipe or soil-pipein a volume large enough to fill the bore of the pipe, in Fig. 95.-SHOWING BAD ARRANGEMENT OF TRAPVENTS. fact, like a water-plug, as shown at c, and which would for the time being leave the lower trap (or traps) without a vent, the evils of which we have just been considering. 12. As my space is limited, I must refrain from further quotations on traps, except to show how certain traps can be made to maintain their seals; and for this purpose I cannot do better than give the results of some tests made upon a stack of soil-pipes still in use in my factory, and which I extract from "Dulce Domum." Fig. 95A represents a stack of 3 in. lead soil-pipe which was fixed in 1881, with three closets upon it (G, F, and L) for the use of the people in my factory. The pipe was fixed of this small size as I was satisfied that it was large enough for its purpose, and that it would at the same time afford severer tests to be made upon the seals of the traps fixed upon it when experimenting. I ought just to say, in passing, that this 3 in. pipe has never once stopped up or given the smallest trouble, though the closets have been used by between thirty and fifty people daily for the last ten years. An anti-syphoning pipe is fixed, as shown by the thin lines, under the control of stop-cocks, for experimenting purposes-that is, from the lowest branch upon the stack a 2 in. lead pipe is fixed, and continued up and connected to the stack a little above the highest branch, with a 2 in. branch into it from certain branches on the stack for the proper ventilation of the traps. And the following results, out of many more which might be quoted of a like nature, show clearly enough the value of fixing anti-syphoning pipes. In throwing large bodies of water down the stack through the upper closets, the greatest strain was brought to bear upon a trap fixed at м; and, as shown by the tests (3h.), an Anti-D-trap fixed at this crucial point, and when properly ventilated, stood a series of tests stronger than it is ever likely to sustain in practice, being left, after twelve discharges through the main pipe, with 1 in. seal. Fig. 95A.-SHOWING A STACK OF 3 IN. SOIL-PIPE, FOR TESTING THE CAPABILITIES OF A SMALL-SIZE PIPE, AND FOR EXPERIMENTING WITH TRAPS, reduced from my work, "Dulce Domum. (1h.) "With a pailful of water thrown down each of the 'hopper' class of closets, B F G, and with the valve-closet basin, D, filled to the brim and emptied sharply, and with the water from two small supply cisterns running into the two water-closets, F and G, as well, making in all about 15 gallons discharged into the main pipe at one time-the 2 in. trap-ventilation, R v, being in use-a 2 in. 'Bower' trap fixed at J, on the 2 in. branch, K, was syphoned; and a 9 in. 'Helmet' D-trap fixed on the 3 in. branch P, at N, had its water lowered in. (2h.) "With another discharge of water as last, without refilling the traps, the india-rubber ball of the 'Bower' trap floated away from the dip-pipe, and the water was lowered enough in the trap to pass smoke through it into the room from the main pipe. The 'Helmet' trap lost in. more water by the second discharge, but it took ten further discharges to syphon this trap. (3h.) "With the twelve foregoing discharges (15 gallons of water at a time) the ventilated 'Anti-D-trap' at м did not lose in. depth of water, i.e., after the twelve discharges this trap had still 11⁄2 in. depth of seal. (4h.) "With a 11⁄2 in. 'Bower' trap fixed at J, instead of a 2 in., a discharge of water through the main pipe as before completely syphoned it. After two such discharges smoke was sent through the trap into the room in volumes, by using an Asphyxiator,' and sending the smoke into the main pipe from the top, at ▲, above the roof. (5h.) "With the 2 in. branch, K, lengthened, and the 'Bower' trap, either 1 in. or 2 in., standing 16 ft. away from the main pipe, there was little, if any, difference; for in similar trials to the last the trap lost its seal, both waterseal and mechanical' seal. (6h.) "With a similar discharge as before, a 1 in. 'Du Bois' trap, a 11⁄2 in. and 2 in. round-pipe trap fixed at J, on the branch, K, were each syphoned in succession. A 4 in. L ditto lost 11⁄2 in. depth of seal in the first discharge, and after the second discharge the water stood in. below the dip. (7h.) "With a similar discharge, a 2 in. 'Eclipse' trap, fixed in the same position as last, was syphoned in every trial. A 4 in. 'Eclipse' trap lost in the first discharge in., second in., and the third discharge syphoned it. (8h.) “With a 14 in. ‘Anti-D-trap' fixed in the same position, and with a similar discharge of water, this trap was also syphoned. A larger size 'Anti-D-trap' held its seal much better. (9h.) "With a small 'Narrow-band' D-trap-11⁄2 in. between the cheeks, and with 11⁄2 in. ‘out-go '—fixed on the branch, K, a similar discharge of water as before lowered the water 1 in., another discharge lowered it in. more, the third discharge a little more, and the fourth discharge syphoned it. With a full-size Narrow-band' D-trap it took forty discharges to syphon it. The first discharge took out in., second in., and seven succeeding discharges took each in. (10h.) "With a full-size 'Helmet' D-trap, fixed as last, the first discharge lowered the water in it in., second in., third in., and the five succeeding discharges took out by each discharge in." |