Service-reservoirs and filters near towns, especially where manufactures are in saying that the magistrates had taken a wrong view of the clause. To use the words of Mr. Justice Lawrance. it is no more necessary to prescribe works to be done to abate a nuisance of black smoke than it is to abate a nuisance caused by keeping a pig '." - Ed.

extensively carried on, should always be covered, to prevent the access of aerial pollution, and to exclude the sun's rays. Filter-lieds may also, if neglected, be a source of pollution, the water having to pass through a layer of decomposing matter.

In towns supplied with river-water, actual sewage from other places may always be present.

When water is raised from deep bores. and filters are not required, avoidable pollutions at the source are almost entirely absent. Of course, adjacent villages or towns, situate over the same water-bearing strata, and lying beyond the bores in a direction contrary to the flow of the subterranean water, may, through leaky cesspools and the like, contribute impurity. But at the actual bores perhaps no avoidable polluting agencies exist, save improprieties of workmen employed in adits, etc, and. in times of scarcity of water, aiding the supply of the bores by turning into them surface-streams, if there be any near.

(2) Few chances of pollution exist in the mains. Ball-hydrants and defective joints may admit a little dirt when the water is turned off; also during repair, or the affixing of new services, some may enter, but not to a serious extent. Farthy matter and rust in "dead-ends" are most in evidence. These may be classed as intestinal irritants, and are of course objectionable, but scarcely come under the head of Pollutions. They do not add permanent injury to the water, as they readily settle to the bottom of a vessel, leaving the supernatant water free from injurious solutions.

(3.) In the service-pipes and house, further dangers exist. Soft water has a solvent action upon lead, and much has been said as to the chances of pollution from lead pipes and lead-lined cisterns, where the water is obtained from lakes. This was especially the case in Glasgow, when that city was first supplied from Loch Katrine, but little or nothing is now heard of evil consequences arising there from this cause, although the sen-ices continue to be made of lead.1 It is, however, a wise precaution not to use water which has remained long in the services, - over-night, for instance.

Probably the greatest danger arises from porous lead pipes laid near leaky drains or yard-sinks. When water is shut off from the mains, as in intermittent supplies, or during repairs, a partial vacuum is formed in the higher parts by the continued drawing off at a lower level. At these times, liquid from outside may be drawn into such pipes through the lead itself.

Services should never be laid near drains or through polluted soil, for even good piping is often burst under the pavement, near where it emerges from the ground to supply a yard-tap. The ground immediately surrounding a yard-gully, which has a separate top-stone badly fixed upon it. is often saturated with sewage in a very foul state of decomposition. If the pipe which supplies the yard-tap is brought out of the ground close to this gully, it will pass through this filth, so that a crack in it at this point is especially dangerous, and the more so because such a burst, if small, may be allowed to continue, as it causes little or no inconvenience to the occupier of the house.

1The degree of hardness of Glaagow water is only .8. In Dublin, where the water possesses 2 degrees of hardness the water-services are made of an alloy of 96 1/2 parts lead and 3 1/2 parts tin. In neither city are there any known cases of lead poisoning caused by the water-supply.

Disused water-supply pipes are sometimes cut, doubled up at the end. and left buried in the ground. Amongst several such eases known to the writer, was one where the floor of a town cow-byre was in one part always wet. Excavation in the urine-saturated floor revealed a branch water-pipe 10 treated which was leaking. Filth must have been drawn into that pipe when the water was shut off from the main.

Where buildings are being pulled down for street-widening, Ac, especially in towns where stop-cocks are not provided on the services in the street, the pipes should be entirely removed from the main.

The Inspector can easily detect a leakage underground by pressing the against the tap, or by resting one end of a poker, or even a walking-stick, against the pipe or tap, and applying his ear to the other, when the hiss of the escaping water will be heard. Before commencing the test, care must be taken to ascertain that all the taps in the house are closed, not forgetting the ball-taps in cisterns.

To connect a water-closet directly to a water-service pipe is surely a practice only of the past, but relies of this work may still exist It is not long sin police-station in a large town was found to have a closet in each temporary cell, all so fitted, the water being turned on from a tap outside To open such a tap when the water was "off" would admit an offensive in-draught to the water-pipe.

The water in a cistern which has a w.c Hush-pipe connected to it, cannot be fouled in the same way as that in a service-pipe joined to a w.c. basin, and it would be difficult for the inspector to prove such an arrangement to be a nuisance, unless, as is sometimes the case, an air-pipe be turned over into the cistern from the flash-pipe. It will be seen from Fig. 666 that this air-pipe provides a din aerial communication between the w.c and the water in the cistern at all times when the flush-pipe is not in use. Such a pipe is provided to ease the pull of the valve on being returned to its seat, and to permit the free descent of the water Left in the flush-pipe after the valve is down. It is turned over into the cistern, because, when the first out rush of water meets the resistance of the air in the flush-pipe, some of it might be forced upwards out of the air-pipe, to fall on the floor below, but for this bend, which returns it to the cistern.

Fig. 666.   Faulty Connection of W.C. Flash pipe and Cistern.

Fig. 666. - Faulty Connection of W.C. Flash-pipe and Cistern.