256 Profetisor Ehrenberg on the Fo.snil Aiiiiiials 



but I must remark, that the number of observations I have 

 made at more than 150 fathoms deep is very considerable. 



The various ramilications of the great adit in the Gwennap 

 mining district, have an aggregate extent of between thirty 

 and forty miles. It drains a tract of about 5550 acres in area, 

 and discharges neai-ly 1500 cubic feet of water per minute. 

 Rather less than one-third of this stream is collected at the 

 adit level, whilst the remainder is pumped up from a mean 

 depth of about 190 fathoms. Its temperature varies between 

 60°-5 and 68°-0, and is, on an average, more than 12° above 

 the mean of the climate. 



The subject of subterranean temperature attracted atten- 

 tion in France and Germany long before it did so in this 

 country.* Though I have made some progress in a compa- 

 rison of the results there observed with those obtained here 

 (and such an inquiry would embrace many points of interest), 

 1 must defer its completion until a more convenient opportu- 

 nity ; as, in this communication, I have purposely confined 

 myself to my own observations in Devon and Cornwall. 



4 Clarence Street, Penzance, 

 16</f January 1043. 



Summary of Results on the Fossil Animals of the Chalk For- 

 mation, still found in a living state. By Professor Ehren- 

 berg of Berlin. t 



It should be the endeavour of one who has collected new 

 facts not merely to bring them accurately and clearly under 



* M. Daubuissoi), des Mines de Freiberg, i. p. 258 ; ibid, iii. pp. 151-18C- 

 200 ; M. de Trebra, Annalcs des Mines, i. ( 1816), p. 377 ; ibid. iii. (1818, obser- 

 vations made 1815-7), P- 59 ; M. Hassenfratz, ibid. i. p. 378 ; M. Lo Baron 

 Cordier, Sur la Teuipe'rature de I'interieur de la Torre, Memoires de i'Aca- 

 deinie des Sciences, vii. (1827) ; M. J. Levallois, Annales des Mines, iii. 

 (1833), p. 620 ; M. Eeicli, Beobachtungen uebcr die Teinperatur des Gesteins 

 in verscliiedenen Ticfen in den Gruben des Sachsiscben Erzgebirges in den 

 Jaliren 1830 bis 1032 ; Prof. Bischof, Edin. New Phil. Journal, xxiii. (1837), 

 1). 330 ; ibid. xxiv. (1838), pp. 132-252. 



t Extracted from page 160, 161, 162, 163, 164, of a memoir in the Berlin 

 Memoirs for 1839 ; but read before the Academy on the 17th and 31st of Oc- 

 tober, and 16th Februai-y 10-10. Translated for and inserted in No. XI. of 

 Taylor's Scientific Memoirs. 



