36 COSMOS. 



to whom we are indebted for a complete series of very deli 

 cate apparatus for determinations of temperature at great 

 dfpths in the sea and in springs, the surface of the basin 

 of the well at Grenelle lies at an elevation of 36.24 metres 

 or 119 feet above the level of the sea. The upper outlet 

 of the ascending spring is 33.33 metres or 109.3 feet higher. 

 This total elevation of the ascending water (69.57 metres or 

 228.2 feet) is, when compared with the level of the sea about 

 196'8 feet lower than the outbreak of the green sandstone 

 strata in the hills near Lusigny, south-east of Paris, to 

 whose infiltrations the rise of the waters in the Artesian 

 wells at C i:enelle have been ascribed. The borings extend 

 to a depth of 547 metres or 1794.6 feet below the base of 

 the Grenelle basin, or about 510.76 metres or 1675 feet 

 below the level of the sea ; the waters consequently rise to a 

 total height of 580.33 metres or 1904 feet. The tempe- 

 rature of the spring is 8l.95 F. ; consequently the increase 

 of heat marks 1 F. for about every 59 feet. 



The boring at the New Salt Works at Eehme is situated 

 231 feet above the level of the sea (above the watermark at 

 Amsterdam). It has penetrated to an absolute depth of 2281 

 feet below the surface of the earth, measuring from the point 

 M here the operations were begun. The salt spring which, 

 when it bursts forth, is impregnated with a large quantity 

 of carbonic acid, lies therefore 2052 feet below the level of 

 the sea, a relative depth which is perhaps the greatest that 

 has ever been reached by man in the interior of the earth. 

 The temperature of the salt spring at the New Salt Works 

 of Oeynhausen is 91 04 F., and as the mean annual tem- 

 perature of the air at these works is about 49. 3 F., we 

 may assume that there is an increase of temperature of 

 1 F. for every 54.68 feet. The boring at these Salt Works 34 

 is therefore 491 feet absolutelv deeper than the boring at 



ratus, by Arago, in 1840, at a depth of 1657 feet, when the borer had 

 left the chalk and was beginning to penetrate through the gault. See 

 Cosmos, vol. i, p. 167, and Comptes rendus, t. xi, 1840, p. 707. 



34 According to the manuscript results given by the superintendent 

 of the mines of Oeynhausen. See Cosmos, vol. i, pp. 148, 166 ; and 

 Bischof, Lehrbuch der Chem. und Phys Geologic, Bd. i, Abth. 1, s. 154 

 163. In regard to absolute depth, the borings at Mondorf, in the 

 Grand Duchy of Luxemburg (2202 feet), approach most nearly to those 

 at the new salt works at Oeynhauseu. 



