"I now exhibit two pieces to the Academy: one comes from the service-pipe of the Faubourg Saint-Antoine, laid down in 1670, at the time when the pump of the Bridge of Notre Dame was erected; it is therefore more than 200 years old, and in the interior the impression of grains of sand is still to be seen. The other was taken up from a side street of Saint-Germain Market; it is somewhat less old, but equally unblemished.

1 Varro, "Marcus Terentius," a learned writer at Rome, B.C. 116.

- W. S. S.

2 A metre is 39.263 inches English.- W. S. S.

3 A Kilometre Is 1,000 Metres

W. S. S.

"It may be added that the leaden pipes become firmly and rapidly coated with a thin crust1 which prevents the water coming in contact with the lead.

"The harmlessness of leaden pipes appears to me proved by these facts, which explain why they are in use in all the towns of France, and in most European cities, without ever having given cause for complaint.

"M. Le Blanc has undertaken other experiments, by leaving the lead in water for a much longer period (than nine or ten hours). I quote his own words: -

"'On the Action of Waters upon Lead.

"'Chemists have long known with what facility lead becomes oxidized when immersed in distilled water in contact with air. Very small white shiny crystals of the hydrated oxide of lead are very rapidly formed, their quantity augmenting until a copious sediment at the bottom of the vessel has formed; the same obtains with pure rain water.

"'On the contrary, water containing a given quantity of salts, principally from selenitic wells, does not attack the lead under the same conditions at all.

"'such are the results of experiments made by Professors of Chemistry during the last forty years in public lectures, and M. Dumas never omitted to place them before his class at the Sorbonne.

"'Chemists have often remarked upon the harmlessness of lead with regard to potable waters, circulating in pipes of this metal, because of the saline matters which preserve the metal from oxidation.

1 Carbonate Of Lime

W. S. S.

"'No doubt it would be difficult to give an explanation of these facts, but they seem of the same kind as those which have been established with regard to iron, which can be preserved without oxidation in distilled water, even when aerated, if only a few drops of an alkali be added to it, whilst it is oxidised rapidly in pure aerated water. But it is curious to observe that by augmenting to a certain extent the proportion of alkali, oxidation can be facilitated.

"'Which salts are the most efficacious, when present in minute quantities, in preventing oxidation of lead in contact with water? Salts of lime alone are unquestionably so, even in the smallest proportions; in the absence of lime other salts are capable of protecting lead, in quantities of 0.1 gramme per litre. Nevertheless, after from twenty-four to thirty hours the water becomes faintly coloured by sulphuretted hydrogen; but this oxidation soon ceases. The following experiments were made to ascertain the particular influence of different salts.

"'solutions were made with sulphate of soda, chloride of sodium, chloride of potassium, sulphate of magnesia, the strength of each solution being 0.l gramme per litre. The lead was immersed in these for twenty-four hours, when the water became coloured by sulphuretted hydrogen, but the solvent action did not continue, and it may be said that the solutions in question are without notable action upon lead, for, at the end of ten days, the re-agent did not produce any real precipitate.'

"Upon the whole there is absolutely no danger of poisoning from the use of water flowing through leaden pipes.

"Furthermore, in the "Journal des Savants" (October, 1871, p. 488), one reads: -

'"It may not be inopportune to draw attention to a fact not sufficiently known to the public - namely, that rain waters alter leaden and zinc vessels more than waters containing salts in solution, well waters for example. The result of this is that these latter waters may remain in a leaden vessel without attacking it, and without becoming poisonous, while rain waters, free from saline matters, dissolve oxide of lead and thus become poisonous. This observation, quoted from Guyton de Morveau, is perfectly true. I have verified it at the time of my investigation on the waters of the Bievre.'"

8. In this advanced age of sanitary knowledge (in the year 1891) it ought not to be necessary to lay any great stress upon the positions of cisterns, or upon the waste-pipes for cleaning them out. But even to-day cisterns are often so fixed that only an expert can get into them; and certainly no maid-servant or member of the family could get at them to clean them out without risk of drowning, or some other dreadful catastrophe, as falling down a staircase, or through a skylight. But though such cisterns may be inaccessible for ready cleansing, they are often accessible enough to bad air; for although they are not now fixed inside water-closet apartments, or only rarely so, they are often fixed at the top of staircases into which doors from several closets open. And they are still fixed in scullerys, and places where the vitiated atmosphere of the house can be absorbed by the water in them.

9. As, at all times to insure a ready supply of water, it is essential to have a storage (Art. 2), it should be stored in a proper cistern-room, where the cisterns could be readily got at, and where no vitiated air could reach them, and the cisterns should be covered over to keep out dust, etc. (m, fig. 143).

In most cases where slate or iron cisterns are fixed in cistern-rooms over important parts of the house, it will be found advisable to fix lead safes under them, not only as a wise precaution against breakage and leakage, but also to protect the floor, when of wood, from condensation droppings. The overflow-pipe from the safe must discharge into the open air, standing out 2 or 3 ins. clear of the wall, as shown at s o, fig. 143. And if this overflow-pipe is also made to answer the purpose of taking away the overflow from the cistern, as shown at c o, the size of the pipe should be about twice the size of the ball-valve.

10. Although there is no risk of any closet air passing back through a service-pipe to a cistern 20 or 30 ft. away, where a self-closing supply-valve is attached to the closet, and the branch supply-pipe is trapped (i.e., so bent that a seal of water should remain in the pipe in case the main service-pipe and cistern should ever get empty), for the sake of sentiment it is better to entirely separate the closet supply from the cisterns and services which supply the general draw-off, etc., for potable purposes, etc. - i.e., no closet, slop-sink, or urinal should be supplied direct from a service-pipe or cistern which supplied a draw-off cock for any other purpose. Where flushing-cisterns are employed for flushing closets, slop-sinks, and urinals, this is simple enough, as shown at v w, fig. 143, and l, fig. 160. (Chap. XXXII., Art. 3.)

11. As most waters form a sediment, and as all waters take up impurities, proper provision must always be made for cleaning out cisterns; but this cannot be done through the ordinary overflow-pipe. It is necessary, therefore, to fix a waste-pipe from the bottom of the cistern, and to continue it to some place of discharge where it would do no damage, and where no bad air could enter it. All plumbers do not remember this, nor are they always reminded of their errors by architects; and even the sanitarian sometimes overlooks such a treatment of cistern-waste as could not be considered but unsanitary. I have only recently come across two or three instances of bad treatment. In one case the bath-waste delivered into a small cistern-head, into which also emptied the cistern-waste, and the bad air driven out by the discharges from the bath passed readily enough up the cistern-waste to contaminate the water in the cistern. In another case the waste-pipe from a tier of sinks delivered into a channel, and close beside it stood the open end of the cistern-waste, and the foul air which was driven out by every discharge of any one of the sinks upon the stacks passed readily enough up the cistern-waste. The mouth of the overflow-pipe or standing-waste should be so placed and so arranged that any cold air which might find its way through it should not impinge upon the ball-valve, service-pipe, or water, to freeze them. And where several cisterns are connected together, the overflow should be taken from the cistern in which the ball-valve is fixed.

12. In fig. 162 an illustration is given of the way waste-pipes from cisterns were often treated some ten or fifteen years ago; and even now this bad practice is followed where men are non-observant, or are slow in learning the right principles of sanitation.

13. All waste-pipes, as well as overflow-pipes from cisterns, whether storing water for closet purposes or dietetic purposes, should discharge into the open air, well away from all places where foul or contaminated air could enter them. Where such pipes can be made to discharge into a roof-gutter or on to a flat, there would be nothing to trouble about - except frost; but to take them into a rain-pipe head, into which also emptied either a sink-waste, lavatory-waste, or even a bath-waste, would be to run great risk of getting foul air into the cistern-room, as shown by the arrows in fig. 162. But though the evil would be reduced by taking the cistern-waste into a pipe-channel or stone-channel in communication with a self-cleansing disconnecting-trap, the arrangement would not be perfect, especially if dirty water waste-pipes also discharged into the same channel. Where the stone-channel or channel-pipe lead into a large gully-trap, the evil would be aggravated, for the discharges into it would stir up any foul decomposing matter in the gully, and the bad air thrown off from such agitation would pass freely enough into the cistern-waste.

Fig. 162. - Section of a Cistern and its Waste-Pipe. Faulty Arrangement.

14. With a brass plug-and-washer fixed to the bottom of the cistern, and soldered to the under waste-pipe, the air communication is cut off, except during the time the cistern is being cleaned out; but a chain affords no control over the plug in case it is desired to replace it during the time the cistern is being emptied; but with a standard-plug, as in the case of a trumpet-waste, the plug could be replaced instantly, and at pleasure. But even with a solid plug the discharging end of the cistern-waste should be carried to a place where no bad air would enter it.

15. Where the water does not require to be filtered, it is a good plan to lay on a service to some convenient place of draw-off direct from the communication-pipe from the water company's main.

16. I have no space here to go into the question of filters, and having dealt with it somewhat at length in another work, I simply remind the reader that filters may, and often do, become contaminators from want of proper attention.