US 



THE CIVIL ENGINKI<:R Ai\D ARCIIITIXTS JOURNAL. 



[April, 



stance), but ihoy can obtain that result with less than nine-elevenths 

 of the j)o\vcr employed by their transatlantic brethren. 



It is however to be observed that the qvianlitv of water boiled oil', 

 and consequently the expenditure of fuel would be greater in the Eni;- 

 lish engines of ^'92'11) horse power in the American engines of 111) I-:}, 

 owing to the steam in the latter being expanded in the lylinder; but 

 it is evident that, by adopting the principle of expansion' in the Eng- 

 lish engines, the saving of fuel would be in proportion to the saving 

 of steam, and nught be carried even much farther than in the engine 

 of the Rochester. 



ABSORBENT ARTESIAN WELLS. 

 By Hyde Clarke, Esq., C.E., F.L.S. 



"The plan of artesian wells for the supply of water, we have mainly 

 derived from our neighbours the I<>ench, and it is one which has been 

 frequently canvassed in your Journal. I have now to call the attention 

 of your readers to another application of boring, which in the present 

 advanced state of geological knowledge and mechanical science may 

 pel haps be productive of some advantage here. It is that of absorbent 

 artesian wells, or cesspools, a system successful on a small scale, but 

 which I am not aware has been carried to the same extent as in 

 France. 



The following account of absorbent artesian wells at Paris is princi- 

 pally derived from the report hereafter referred to made to the Pre- 

 fect of Police by M. Parent Duchatelet, the well known writer on 

 hygienic police. The reasoning will apply equally to London, as the 

 London basin is much the same as that of Paris, with the omission of 

 the tertiary building stones. 



The ci ty of Paris, for the purpose of suppressing the Laystall at Munt- 

 faucon, has within the last few years established a new one in the 

 forest of Bandy. Altliough, this latter in 1833, received only a quarter of 

 the soil daily supplied by the city, it occasioned, even at that period, 

 great inconvenience both with regard to conveyance and dessiccation, 

 on account of the existence of a stratum of water, the height of which, 

 varying according to the season, often reached the level of its basin. A 

 part of the fluid in excess might, it is true, have been turned into the 

 little brooks, »hich spring up at a short distance, but as these brooks 

 all run into larger streams ami cross several villages and jnavate pro- 

 perties, and indeed the town of St. Denis, would have caused just 

 conqjlainl on the pari of a manufacturing population of ten or twelve 

 lliousand souls, for w hich the water is required to be extremely pure. 



It was in order to surmount these <lifficulties that the contractors for 

 the Bondy Laystall, stimulated by examples to which we shall here- 

 after have occasion to refer, thought of turning into the earth, at a 

 considerable depth, the superfluities of their reservoirs. ]\I. Mulot, G.E., 

 was in consequence charged with the boring of an artesian well, in- 

 tended, not for the purpose of bringing water to the surface of the 

 earth, but to absorb that which should be sent down its shaft. This 

 attempt was Clowned with conq^lete success; the boring having been 

 carried to a total depth of 243 feet 7 inches, (7Ini7l) showed two 

 absorbing strata, one from 133 feet .5 inches to U>5 feet 4 inches in a 

 mixture of chalk and silex, and the other from 211 feet 11 inches to 

 243 feet, in argillaceous sand, and green and grey sanils containing 

 lignites and pulverised shells. By the first, GO or 7') cubic yards were 

 absorbed in four and twenty hours, and by the second 140 cubic yards 

 in the same time. 



The Prefect of Police, alarmed at the consequences which might 

 arise, allecting the salubrity of the waters under the surface, from such 

 a large mass of dirty fluids being mixed with them, ordered the pro- 

 cess to be suspended until a committee of the Board of Health had 

 examined into its o|)eration. 



In the Paris basin are several distinct strata of water, separated 

 from each other by impermeable layers of dillereut kinds. The first, 

 that is to say the most superficial of these strata, is not to be found 

 under the city of Paris; it is only met with on the tops of the hills 

 and |)lateaux which surround it on all sides ; it is retained by a thick 

 bank oi clay which is found above the masses worked as plaster quarries. 

 For this reason, on these plateaux, bOO feet above the level of the 

 Seine, the wells are often only two or three yards deep. This stratum 

 is evidently formed by the filtration of rain, and by the condensation of 

 vapour on the surface of the soil of the plateaux. 



The second stratum, which probably depends on the same causes, 

 but which extending under Paris and throughout the valley of the 

 .Seine near it, collects its waters from a much larger surface of country, 

 and flows across sands which are between the plastic clav, and the 

 building chalk {calcaiix u ktlir, wanting in the London "basin;, it 



supplies all the vrells in Paris, to the number of twenty-live or thirty 



thousand. 



The strata of water below the two first can only be reached by bor- 

 ing: their nnmber and the depth at which they are to be found vary to 

 a great degree; sometimes they are entirely wanting, they do not 

 always ascend, and if they reach' the surface "through the well, their 

 overflow is not the same in places nearly contiguous. It is very im- 

 ])ortant to be observed that these strata are so much the more abundant, 

 as they are found at a greater depth, and that they have a rapid current, 

 which gives them the character of subterranean rivers. 



Numerous facts on the contraiy prove evidently that the two first 

 strata have no current, and are completely stagnant. The first, that 

 which is above Paris, is very scanty, and there is a risk of infecting it 

 by sending into it a large quantity of dirty water. To be convinced 

 of this, it is enough to observe that the waters which came from the 

 side of Mount Valerien are excellent, and those from JVlontmartre are 

 not drinkable on account of the number of cowhouses and dung-pits 

 which lose there all their liipiid portions. The second stratum, that 

 which supplies the wells of Paris, was formerly of good ([ualily, anil 

 was used for drinking by the inhabitants of the houses, and neighbour- 

 ing villages. It has only been since the increase of cessjiools, and 

 especially since the introduction of privies into houses, that is to say 

 from the time of Francis the First, that the water has begun to deteri- 

 orate, and that the Sieine water has been obliged to be used for drink. 

 It must not, however, be thought that the influence of dirty and infect- 

 ing waters extends bevond a very narrow boundary. Thus it has been 

 found that around the great lavstalls which were formed by the city 

 of Paris near the barriers of Montreuil and Fourneaux, the well-water 

 was never affected beyond a radius of 150 or 200 yards. The village 

 of La Chapelle near Paris, not being able on account of its situation 

 on depressed ground, to get rid of its dirty water, was obliged in order 

 to dis])ersc it to dig immense cesspools which swallow u\> all that is 

 thrown into them. Besides a population of four thousand souls, the 

 village of La Chapelle contains an enormous quantity of horses, cows, 

 pigs, &c., and yet the wells near the cesspools have never been in- 

 fected beyond two hundred yards from them. A still more decisive 

 fact than the |)receding is all'urded by the history of the laystall of 

 Montfaucon. Towards the close of the last century, before the conduit 

 was made which discharges into the Seine, tlie surplus of the basins, 

 one of the contractors for this laystall tliought of digging in the lowest 

 jiart a series of wells of large iliameter, of which the bottom touched 

 the stratum 3up])lying the neighbouring wells. He succeeded by this 

 means in getting rid of the troublesome water, and the wells around 

 were infecled, but not beyond a radius of 200 yards. A very long period 

 is required to enable the gradual removal of water, by means of the 

 alimentary stratum, to cleanse an infected w ell, of its bad qualities. A 

 manufacturer in the Faubourgh .St. Marceau wishing to get rid of the 

 hot water of his steam engine at small expense, thought of sending it 

 into a difl'erent well from that which fed his boiler. For some months 

 this produced no inconvenience ; but gradually the water in the neigh- 

 bouring wells got warmed, and at last to such a degree that it could 

 not be used for many purposes. The warm water was obliged to bo 

 sent in another direction; bat it took ei^hlun monllis to bring the wells to 

 their primitive temjierature. We must add however, with regard to 

 the gradual renewal of the water in the wells of Paris on account of 

 the ever increasing consumption necessary for industrial purposes, that 

 the suppression of the cess])Ools which the police no longer allow in 

 the houses, and especially the establishment of moveable water closets, 

 or at least with staunch walls, will prove so many causes which will 

 jirobably in a few years carry oil the bad qualities of the well water. 



As to the lower strata, their abundance, and the rapidity of the cur- 

 rents which prevail in them, prevent us from assimilating them to 

 wells, or from regarding the tleperdition of dirty water, even in any 

 very great cjuautity, as exercising a pernicious influence. In 1789, 

 the architect Viel being employed by the Hospital Board to free 

 Bict tre from the rain and household water, as well as from the urine 

 and fecal matters produced by a population of more than four thousand 

 souls, he thought of directing the flow towards some old quarries deep 

 enough to reach the stratum supplying the neighbouring w-ells. But 

 wishing to have a permanent infiltration, he sought the second stratum 

 by means of a wcU 1.5 yards deep from the bottom of the quarry, this 

 well is ten yards broad at top, and ends in a bore of large (limensions, 

 thus forming a cistern with which the several galleries of the quarry 

 comnumicate. It was in the month of November, 17'.I0, that all the 

 water of Bicitre was introduced into tliis cesspool, and from that day 

 it has always run olf easily. It is true that the wells situated on 

 the right bank of the small river Bicvre, 150 or 20(1 yards from this 

 cesspool, have been infected ; but that arises from a circumstance 

 purely local, rain water after storms, accumulating in the galleries, 

 whieli commmiicate with the cesspool, and exercising an eiwrmous 



