FARMERS' REGISTER— ARTESIAN WELLS. 



453 



Carrrieaux. 



Depth. Temp. Cciili. 



Water of the well Veriac, 6 2 metres 12° 9 



Water of the well Bigorre, 115 " 13 15 

 Rock at the bottom of Ravin 



mine, - - 181 9 " 17 1 



Rock at the bottom of Cas- 



tiilan mine, - - 192 « 19 5 



Littrtj. 



Surface, - - " 11 



Rock at the bottom of St. 



Charles mine, - 90 " 16 135 



Decise. 



Water of the well Pclisson, 8 8'' 114 



Water of the Puits des Pa- 

 vilions, - - IG 9 " 11 67 



Rock in the Jacobe mine, 107 '■ 17 78 



" " " 171 " 22 1 



These observations were made with extreme 

 care, so as to avoul the influence of all local causes 

 that mifyht vitiate the results. 



To these might be added the numerous and ac- 

 curate observations oi Daubuisson in Saxony and 

 Brittany — De Trebra in the ibrmer, and Fox in 

 Cornwall. Our own continent has, as yet, witness- 

 ed but a single observation of the kind; one made 

 by the learned and cnterprismg Humboldt in the 

 silver mine of Guanaxuato in Mexico. This ob- 

 servation is chiefly valuable on account of the 

 great depth at which it was made, viz: 522 metres, 

 or nearly 1800 feet. The mean temperature at the 

 surface being 60° 4 of Fahrenheit; he found the 

 thermometer below to stand at the enormous 

 height of 96° 44. 



But the experiments bearing most directly on 

 the query last proposed, are tliose which have 

 been made in vanons Artesian Wells in Europe. 



The following results were obtained by M . De 

 Bellevue, in a well of this description on the sea 

 side near Rochelle. 



The well at the time of the first experiment 

 was 3^ inches in diameter, and 316 feet deep; filled 

 with brackish stagnant water to the height of 294 

 feet. The external air being at 51° Fahrenheit, 

 the thermometer after remaining at the bottom 24 

 hours stood at 61°. At eleven feet below the sur- 

 face the water had a temperature of 56° 6. The 

 same Avell being afterwards sunk to 370 feet the 

 thermometer, after standing 25 hours, showed a 

 temperature of 64° 6; making an increase of 3° 6 

 for an additional depth of 54 teet. A repetition of 

 the observations gave precisely the same result. 



An Artesian Well in the neighborhood of Vi- 

 enna gave the following temperatures. 



Mean temperature at the surface. 50° 44 Fahr. 



At a depth of 62 20 feet 52 25 " 



do. Ill 68 do. 52 90 " 



do. 300 42 do. 56 93 " 



Another at Epinay gave, 



At the depth of 30 37 feet 51° 8 Fahr. 



do. 

 do. 



177 76 do. 55 94 do. 

 219 45 do. 57 20 do. 



In these observations the depths were estimated 

 in metres, and the temperatures measured on the 

 Centigrade scale. I have reduced the former to 

 English feet, and the latter to degrees of Fahren- 

 heit, for the sake of a more convenient comparison, 



with observations which may hereafter be made 



in this country. 



From a review of the observations above re- 

 corded, it will be apparent that although in every 

 instance the temperauire increases with the depth, 

 the rate of this augmentation is not the same at 

 different places. 



The fiiilowing table exhibiting the depth in 

 English feet corresponding to a rise of one degree 

 of Fahrenheit, has been calculated from the num- 

 bers given in Pouillet's Elemens De Meteorologie. 



Ill France. 



At Decise, 27 30 ke\. 



At Littry, 34 58 do. 



AtObservatoryinParis, .50 96 do. 

 At Carmcaux, 63 70 do- 



At Brittany. 72 80 do. 



In Switzerland. 



Near Bex, 47 32 feet. 



la Saxony. 



The mean of several mines, 72 80 feet, 



In England. 



Cornwall and Devonshire, 45 50 feet. 



In jimerica. 



At Guanaxuato, 45 50 feet. 



In the Artesian Well near Rochelle, to which 

 we have already referred, the rate of augmenta- 

 tion was still more considerable than in either of 

 the above examples. There the thermometer 

 rose 3° 6' by an increase of depth amounting to 

 54 feet — which is at the rate of one degree to 15 

 feet. 



Certainly no fact can be more curious or inter- 

 esting than the comparatively high temfjerature of 

 the water in the lower parts of these wells. From 

 the known tendency of warm water to ascend and 

 give place to that which is colder, it is evident 

 that unless there existed some permanent source of 

 heat at the bottom and sides of the well, the dis- 

 tribution of temperature which has been observed 

 could not continue for any length of time — and 

 hence these experiments furnish convincing evi- 

 dence of a regularly augmenting temperature in 

 proportion to the depth. 



The observations hitherto made on the tem- 

 perature of Artesian Wells, have, as we have 

 already stated, been confined to Europe, and have 

 embraced no very great range of depth. Many 

 of the borings in the United States afford an op- 

 portunity of obtaining a much wider extent of 

 comparison, and would therefore, no doubt, furnish 

 still more interesting results. Assuredly this con- 

 sideration ought to be sufficient to invite all who 

 are favorably circumstanced to engage in the in- 

 vestigation. The time and labor necessary for 

 such a course of observations, would be incon- 

 siderable, when compared with the important 

 bearings of the inquiry, and even supposing that 

 a minute degree of accuracy should not be found 

 practicable — great interest will attach to the rudest 

 approximate result. The following hints as to 

 the mode of observation will, it is hoped, be useful 

 in furthering inquiry. 



In order to discover the exact temperature of 

 the water at any considerable depth, the thermom- 

 eter which is let down ought, if possible, to be pro- 



