Hot and Thermal Springs. 383 



example, seems to be the case in the gulf stream on the coast of 

 Aine7ica, where, on hauling up the lead from a depth of 80 or 

 100 fathoms, it is so hot as scarcely to allow of its being handled. 

 Similar spots seem to exist near the Kurile Islands, in Basse''s 

 Straits, and in the Atlantic Ocean where Horner in clear weather 

 observed, at about nine miles' distance from the vessel, a cloud 

 of vapour, which, during a quarter of an hour, continued alter- 

 nately appearing and disappearing from the surface of the sea, 

 and could neither be the smoke of powder nor that of a vessel 

 on fire. Horner considers that this phenomenon may perhaps 

 have been caused by a volcanic eruption. In opposition to the 

 opinion that the bottom of the sea must in very great depths 

 consist of a solid mass of ice, Horner brings forward very con- 

 clusive arguments. 



Lastly, a series of observations were made by Lenz,* on a voy- 

 age round the world, under the command of Captain Von Kot- 

 zebue, in the years 1823 to 1826, with the utmost care and 

 circumspection, so that particular confidence may be placed in 

 them. They yielded the following results: — 1st, Between 45° 

 north latitude and the equator, the temperature of the ocean 

 constantly decreases to the depth of 1000 toises, below which no 

 experiments have been made. 2d5 The decrease of temperature 

 is at first rapid, but becomes slower and slower, and is at last 

 scarcely perceptible. 3d, The point at which the decrease be- 

 gins to be imperceptible, seems to be situated less and less deep 

 the further we recede from the equator. Under latitudes 41° 

 and 32% its depth is 200 to 300 toises ; in latitude 21°, it is 400 

 toises. 4th, The lowest temperature observed in great depths, 

 was 35°.93, and this is about the temperature of all points where 

 the decrease begins to be no longer perceptible. 



According to the third mentioned result, this temperature is 

 found nearer to tlie surface the higher the latitude; it would be 

 interesting to ascertain in what latitude it reaches the surface. 



We will now proceed to the consequences which may be de- 

 duced from the decrease of temperature in the sea and in lakes. 



• Pogfjendorff's Annal. vol. xx. p. 73 and fi)llo«iiig, extracted from a paper 

 read bv I.enz bafore the Academy of St Petersburg, on the 4th of Novem- 

 ber 182f». 



