ARTESIAN WELL. 



ASTRONOMICAL PHENOMENA. 



ARTESIAN WELL AT PASSY. The town 

 of Passy is now one of the western suburbs of 

 the city of Paris, France. It is in the depart- 

 ment of the Seine, and enclosed within the new 

 fortifications. The artesian well here was com- 

 pleted in 1861. It is the largest in the world, 

 and, as such, the difficulties with which the 

 engineer, M. Kind, had to contend are worthy 

 of notice. These were brought before the atten- 

 tion of the Academy of Sciences by M. Dumas. 



The idea of boring this well originated with 

 the necessity of providing pure and wholesome 

 water for the population of Paris, which in a 

 short time had increased from 1,200,000 souls 

 to 1,700,000, thus materially augmenting the 

 causes of infection to which the waters of the 

 Seine are necessarily-subject. Paris rests upon 

 a stratum of chalk about 1,500 feet in depth, 

 covered with about 150 feet of various strata 

 of tertiary soil, and itself resting on nearly 150 

 feet of marl or clay, which is in contact with 

 the green sands from which the well of Grenelle 

 derives its supply. The successful boring of 

 the latter had established the fact that the 

 water which these sands received from localities 

 at a distance from Paris might be made to rise 

 to the surface, and even to 100 and 130 feet 

 above. But the experiment had only been tried 

 for bores not exceeding a diameter of from 8 

 inches to 1 foot, yielding a supply of from 2,000 

 to 4,000 cubic metres of water per day. M. 

 Kind came forward with an offer to bore a 

 well of a diameter of 2 feet, yielding 400,000 

 cubic feet at an altitude of 80 feet above the 

 highest point of the Bois de Boulogne. Though 

 limiting his promises to the yield above stated, 

 he declared his conviction that it would reach 

 1,200,000 cubic feet, an assertion which most 

 engineers considered exaggerated, deeming it 

 highly improbable that an increase in the diam- 

 eter would increase the supply. 



On the 23d of December, 1854, the works 

 were resolved on, and the spot chosen in the 

 neighborhood of the Bois de Boulogne, where 

 the high temperature of the expected column 

 of water might be turned to account. But the 

 enterprise was fraught with difficulties which 

 it required the unflinching perseverance of M. 

 Kind to overcome. 



On March 31, 1857, the bore had already 

 reached 1,737 feet, and water was hourly ex- 

 pected, when suddenly the tube of sheet iron 

 whicli supported the clay was crushed by its 

 pressure at a depth of only 96 feet from the top. 

 This accident it took nearly three years to re- 

 pair ; a shaft of the depth of 1,760 feet had to be 

 dug close to the bore, through all the most dan- 

 gerous strata, and lined partly with sheet, and 

 partly with cast-iron and masonry. Its diame- 

 ter was about 10 feet throughout the two-thirds 

 of its depth and T70 for the rest. It was a 

 work of extreme difficulty. Oast -iron tubes, of 

 the thickness of four-fifths of an inch, were 

 starred or cracked in all directions, as if they 

 were mere glass. More than once the workmen 

 refused to risk their lives in this work, and the 



city engineers had to set the example of per- 

 sonal courage. 



This stupendous labor was not brought to an 

 end before the 13th of December, 1859. The 

 old orifice was then cleared, and the boring re- 

 commenced, and continued without any further 

 accident to the depth of 1,810 feet, when the 

 tube, composed of wood strongly hooped with 

 iron, and ending in a bronze pipe, 6^ feet of 

 which were fitted into the wood, the remaining 

 39 feet being free, stuck fast in such a way as 

 to render all further progress nearly hopeless. 

 However, M. Elie de Beaumont having, upon a 

 mature examination of the specimens brought 

 up by the borer, declared water to be close at 

 hand, it was resolved that the bore should be 

 continued with a small diameter, to be after- 

 wards enlarged, if necessary. Water was found 

 for the first time at 1,900 feet, but, as we know, 

 remained a few feet below the level of the ori- 

 fice. A second tube of sheet iron, 2f inches in 

 diameter, in thickness, and 171 feet in length, 

 40 of which were loopholed in order to let the 

 water pass, was sunk, and soon stopped in the 

 clay. The boring was now resumed, to attain 

 the largest diameter, until the 24th of Septem- 

 ber last, when M. Kind saw not only his prom- 

 ise fulfilled, but even his hopes to a certain 

 extent realized. The bronze tube has remained 

 where it was, but the concentric one of sheet 

 iron has sunk to 1,250 feet. M. Dumas here 

 quotes M. Michal, Inspector- General of the 

 Works of the City, who has arranged in a table 

 the relative variations experienced in the yield 

 of the two wells of Passy and Grenelle ; but on 

 this score we have a later account, stating that 

 the decrease in the latter does not exceed one- 

 fourth of its prior yield. That of the well of 

 Passy was 5,660,000 New York gallons in 24 

 hours. M. Dumas attributes the diminution of 

 the yield at Grenelle to a diminution of pressure, 

 and is inclined to believe that when the tube 

 at Passy shall have been brought to its normal 

 altitude of 256 feet above the level of the sea, 

 the yield at Grenelle will again rise to its former 

 figure, or nearly so. M. Elie de Beaumont has 

 ascertained that the strata traversed at Passy 

 are nearly the same as those met with at Gre- 

 nelle. As to the chemical nature of the water 

 at Passy, it seems, until further analysis, to be 

 nearly the same as that of Grenelle ; the tem- 

 perature is also the same, viz., 28 degrees cen- 

 tigrade. Whether other wells may be bored 

 elsewhere in Paris without injury to the two 

 existing ones is a question which experience 

 alone can decide. The well at Passy has cost 

 nearly $200,000. 



ASTRONOMICAL PHENOMENA. The 

 year 1861 will be remembered in astronomical 

 science for the brilliant comet whicli appeared 

 in the month of July. It had been preceded 

 by a smaller one which was discovered by A. 

 E. Thatcher, of New York, on the night of 

 April 4th. This was a telescopic object show- 

 ing no tail, but with more than usual bright- 

 ness. Its right ascension on the 10th, as calcu- 



