236 M. Arago on Artesian Spring's 



Metres. 



Paris, Mean temperature at surface, + 10.6 Centig 



Do. of Well of Port St Ouen, + 12.9 Depth C6 



Departements du Nord, \ 



. J I, J ri 1 ■ ( Mean temperature at surface, + 10.3 

 andduPas-de-Calais,} ^ ' ' 



Do. Well of Marquette, + 12.5 Depth 56 



Do. WeU of Aire, . . + 13.3 ... 63 



Do. Well of St Tenant, 4 14.0 ... 100 



Slieerness,. mouth of Oie ) 

 -, , . ^, _, }■ Mean temperature at surface, + 10.5 



Medwayintiie Thames ) '^ 



110 



Tours, Mean temperature at surface, + 11.5 



Temperature of artesian well, + 17.5 ... 140 



Depths of the most remarkable Founfaijis which have been opened by 

 the hand of man. 



We have already alluded (page 206) to pits sunk by the Chi- 

 nese to the depth of IbOO feet, in the province of Kia-ting-fou, 

 by which they hoped to procure a supply of salt water ; but as no 

 water ascended the pits, we cannot rank them in the list of wells 

 properly so called. 



The seventh sheet of water, found near Saint Nicolas-d'Alier- 

 mont (see p. 224), was at the depth of 1030 feet. The water 

 from it rose to the surface. As it was not water but coal that 

 was sought for, the works were abandoned ; and the only result 

 that remained, was the formation, without intending it, of a 

 copious fountain, whose waters issued from a source more than 

 1000 feet deep. 



The pit recently sunk at Geneva to the depth of 682 feet, 

 has not reached any body of water which has a tendency to 

 rise. 



At Suresne, near Paris, the residence of M. Rothschild, tlic 

 Messrs Flachat have worked a pit, previously begun by M. 

 Mulot, to the depth of 663 fec-t. This pit has now penetrated 

 the chalk to the extent of 537 feet. The work has been sus- 

 pended, when there is only about 60 feet more of the chalk 

 formation remaining, upon penetrating which, there would be 

 every prospect of finding water. The desirableness of pro- 

 secuting the research, is most apparent. 



The fountain of CheswicTc^ in the Duke of Northumberland's 

 park, projects its water about a yaid above the surface of the 

 soil, and comes from the depth of 582 feet. 



