40 Prof. Bischof 071 the Natural History of 



the temperature is 1754'^5 F. ; " for, according to the above 

 formula, if t be taken equal to 1754°.5, e — 77028 inches of 

 a column of mercury, or l^iLil = 275 1 atmospheres, and MiLiA 

 gives the same number. On the other hand, for a constant in- 

 crease of temperature of 1° F. in 57.1 ft. it advances to a depth 

 of 105627 ft. below the surface of the sea, where the corres- 

 ponding temperature would be 1881°.5 F. ;* for the same for- 

 mula gives e ■=. 92435 inches of a column of mercury, or 3301 

 atmospheres, when t — 1881 °.5, and \^SiU. gives the same 

 value. Presupposing the correctness of the premises, these 

 calculations shew the possibility of columns of lava of M|i-1 

 = 29348 and ISH^ll = 35209 ft. being raised by the power of 

 steam from the respective depths of 88044 and 105627 ft. be- 

 low the surface of the sea, whilst there is an uninterrupted 

 communication between the sea and the volcanic focus. The 

 difficulty mentioned by Gay-Lussac, that the water would, 

 under its own pressure, take the gaseous form before reaching 

 the strata, which are at a white heat ; without being able to raise 

 the lavas, to cause earthquakes, and to support the volcanic phe- 

 nomena ; is consequently also set aside, in so far that the water 

 cannot assume the form of gas under its own pressure before 

 reaching those depths and their corresponding temperatures. At 

 depths greater than 88044 or 105627 ft. below the surface of the 

 sea, if the communication with the sea remained free, a reaction 

 would take place in the column of water. Perhaps the pheno- 

 mena mentioned in chap, xi, on Hot and Mineral Sprinj'js, vol. 

 xxiii. of Ed. New Phil. Journal, and observed by Horner near 

 the Kur'ile Islands, as well as the powerful stream of hot steam, 

 observed by Hoffmann near Vidcano^-f beneath the surface of 

 the sea, probably at the same place where the crater of the cone 

 formerly thrown up at this spot was situated, proceeds from a 

 .similar volcanic effervescence. In general the rising of smoke 

 from the sea during the eruptions of neighbouring volcanos is 

 by no means an uncommon occurrence. % The reflux and the 



* To simplify the calculation, I have supposed the mean temperature of 

 the surface = 32° F. 

 t Loco cit. p. 67. 

 % D. Curbeto (Von Buch loco cit. p. 78) observed a great quantity of smoke 



