(c) Jute. A hempen, unwoven cord, with long, fine fibres, used by plumbers in caulking. This substance produced the strongest capillary action, and acts like very fine hair and lint. Arranged as in Figure 283, a piece inch in diameter transferred 1 inches in fifteen minutes and 2 inches in four and three-fourths hours. Another piece, 1 inch in diameter, transferred 2 inches in fifteen minutes, and the whole 4 inches in four and three-fourths hours. Another piece, supported as shown in Figure 284, raised the water 4 inches, after which the lower end of the long arm dried up, and what water was thereafter raised from the goblet was carried off by evaporation, but not transferred to the lower glass.

(d) Hemp-cord, unravelled and separated into fibres, was in no case able to raise the water above 4 inches from its surface.

(e) Twisted or braided, as it comes in cord for the market, it could not transfer more than 2 inches from glass to glass.

(f) Pieces of linen twine (eight pieces) could not transfer more than inch.

Beyond these points the various substances invariably dried up at their lower ends, after which, of course, whatever water was taken from the upper vessel was removed by evaporation.

Tests were then made on various similar fibrous substances, both in the manner described and also enclosed in small, -inch bent lead tubes, to prevent evaporation from effecting the action. In no case, except with sponges, could the water be raised over 3 inches, and rarely over 3 inches by these substances. The outer arms dried up before the water in the upper glasses was lowered 3 or 3 inches. Without the lead tubes, the outer arms dried up sooner than with them, hence less water was carried over into the lower glasses, but more was lost by evaporation. The loss of water was greater without the tubes, but the action was slower, since the drying up of the outer arms prevented the rapid removal by the combined capillary and siphoning action.

Fig. 286 shows the manner in which tests for the limit of horizontal and inclined distances were made. It was found that an increase in horizontal distance facilitated the drying of the mass, and therefore correspondingly diminished the siphoning action.

I will now place pieces of jute inch in diameter in each of the three glasses on the table, just as you see them represented in the picture, and in a few minutes we will observe the action they have produced. The water stands in each goblet exactly on a line with the top of the glass.

From the experiments I have so far described, and numerous other tests made in the same manner, we learn that the extreme limit of the lifting power of very small quantities of the long, fibrous substances which might lodge in traps so as to exert a capillary action is within three inches. Sponge is the only substance known to the writer as likely to be found in waste pipes which has a lifting power exceeding this. The limit of sponge, even in large masses, appears from the tests made at the same time with the others, to be 8 inches; but as the general shape of a sponge is spherical, and never filiform, and as no sponge large or long enough to extend upwards this distance or anything approximating it, and then down again the same distance into the waste pipe, could possibly be squeezed into a trap without stopping up the waterway altogether, the consideration of this material and all others of similar form need not enter into our calculation.

. Tests With Traps.

Thus far the experiments have been made in the open air in ordinary open vessels. The tests were made in the shade, and in a temperature varying between 60 and 70 degrees F., or the ordinary temperature of house interiors. To render these results of more practical value they should be compared with the tests made on the same materials in the actual positions found in practice - i. e., in the trap itself. The tests were, therefore, made both in detached traps and in traps fixed in position and properly attached to the drain pipe.

Tests With Ordinary S-Traps.

A 1-inch S-trap having 1-inch seal was arranged as shown in Figure 287. A string of jute -indi in diam-

Fig. 287. S Trap having its Water Seal Destroyed by Capillary

Fig. 287. S-Trap having its Water Seal Destroyed by Capillary eter was introduced so as to extend from the bottom of the trap over the outlet and down several inches below the bottom. The experiment was repeated five times, the results each time being nearly identical. In the first half minute the water in the trap was lowered inch. Five minutes sufficed to lower it 1 inch, twenty minuts 1 inches; a half-hour usually sufficed to break the seal, and about three hours was enough to leave the trap almost dry.

Action.

The quantity of jute was afterward increased to 1 inch in diameter, which was the maximum possible, inasmuch as it was sufficient to fill the trap as full as it could ever possibly get in practice. In every case enough water was drawn out of the trap to break the seal in less than half an hour. Two minutes generally sufficed to lower the seal an inch. Hair-felt emptied the trap in from nine to fifteen minutes.

Tests With Pot-Traps.

A number of pot-traps were then tested. An 8-inch pot-trap having 3 1/8-inch seal was arranged as shown in Figure 288, the mass of jute being 1 inch in diameter. It required twenty-four hours to lower the water 1 inches. Two days reduced it 1 13-16 inches; three days, 1 7/8 inches; seven days, 1 15-16 inches. After this no further change took place in the trap. Evaporation was too slow to make any perceptible difference in several days, since the trap was not ventilated.

A vessel of water about the same size and form with the 8-inch pot-trap, but freely open above to the air, so that evaporation could go on, and having a piece of jute 1 inches in diameter hanging over its edge, as in Figure 283, lost 5 inches of water in five days. A portion was carried over as in the 8-inch pot-trap into the vessel below, but the rest was removed by evaporation hastened by the capillary action.