258 ANNUAL OF SCIENTIFIC DISCOVERY. 



found, near the flanks of one of its glaciers, a portion of the ice com- 

 pletely roofing a hollow, over which it had been urged without being 

 squeezed into it. A considerable area of the under surface of the 

 glacier was thus exposed, and the ice of that surface was more finely 

 fluted than ever I have observed rocks to be. Had the tool of a cab- 

 inetmaker passed over it, nothing more regular and beautiful could 

 have been executed. Furrows and ridges ran side by side in the di- 

 rection of the motion, and the deeper and larger ones were chased by 

 finer lines, produced by the smaller and sharper asperities of the bed. 

 The ice was perfectly unweathered, and the white dust of the rocks 

 over which it had slidden, and which it had abraded in its passage, 

 still clung to it. The fact of sliding has been hitherto inferred from 

 the action of the glacier upon the rocks ; the above observation leads 

 to the same inference from the action of the rocks upon the glacier. 

 As stated at the outset, it is the complementary proof that the glacier 

 moves bodily over its bed. 



THE ARTESIAN WELL AT PASSY, FRANCE. 



At a recent meeting of the French Academy, M. Dumas read a 

 paper on the history and difficulties of the above-named work. The 

 idea of boring this well originated with the necessity of obtaining an 

 additional water supply for the city of Paris. This city rests upon a 

 stratum of chalk about 500 metres in depth, covered with about fifty 

 metres of various strata of tertiary soil, and itself resting on nearly 

 fifty metres of marl or clay, which is in contact with the green-sands 

 from which the celebrated well of Grenelle derives its supply. The 

 successful boring of the latter had established the fact that the watei 

 which these sands received from localities at a distance from Paris 

 might be made to rise to the surface, and even to thirty or forty metres 

 above. But the experiment had only been tried for bores not exceed- 

 ing a diameter of from twenty to thirty centimetres, yielding a supply 

 of from 2,000 to 4,000 cubic metres of water per day. An engineer, 

 however, M. Kind, came forward with an offer to bore a well of a diam- 

 eter of sixty centimetres, yielding 13,300 cubic metres at an altitude of 

 twenty-five metres 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 39,600 metres; an assertion which 

 most engineers considered exaggerated, deeming it highly improbable 

 that an increase in the diameter would increase the supply. 



On the twenty-third 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 difficul- 

 ties which it required the unflinching perseverance of M. Kind to 

 overcome; although out of the 58 7 metres which constitute the 

 depth of the new well there were scarcely thirty offering any serious 

 obstacle, and these were situated in the clay either above or below 

 the chalk stratum. 



On March thirty-first, 1857, the bore had already reached 528 

 metres, and water was hourly expected, when suddenly the tube of 

 sheet iron which supported the clay was crushed in by its pressure at 



