26 On the Heat of Springs, [Ju LY, 



monly exhibit the mean temperature of the year ; and that July is 

 the hottest, and January the coldest, month. It would seem that 

 these changes show themselves in small springs 1-J- month later, and 

 in great springs 1|- month later : but the heat of the atmosphere, 

 when once it has reached the medium, changes most rapidly ; while 

 at the extremes it remains some time without sensible alteration. 

 On that account the temperature of springs changes rapidly towards 

 the extremes, and remains long unaltered towards the medium of 

 the temperature of the air; and its increase and diminution follows 

 a very regular rate, on which the most rapid alterations in the heat 

 of the atmosphere have little or no effect. The following observa- 

 tions on a scanty and a more copious spring will show the nature of 

 these alterations more clearly. 



Kallsprohng, at Lasshybackar. Professor spring at Haga, 



In 1809. In 1809. 



30 Mav 44-06° 1 1 September 4874* 



18 August 54-68 16 Ditto 48-56 



2 September . . .55-40 1 October 4«-02 



1 1 Ditto 52-93 10 Ditto 47'66 



18 Ditto 52-16 17 Ditto 17-12 



1 October 49- 10 



9 Ditto . , 46-94 



10 Ditto 46*76* 



17 Ditto 45-32 



It is at least clear from this table that the springs become warmer 

 till towards the beginning of October. Now as the Ohs spring, 

 near Herhalt, remained unaltered on the 25th July, the 7*h 

 August, and the 21st September, I think we must conclude from 

 hence that the temperature of this spring remains always the same; 

 and that therefore the temperature of the earth at the lake Yngen 

 sea is 41°, or 3-.06 less than that of the earth at Upsala. This 

 lake lies in one of the highest spots of Wermeland. From several 

 levelling observations we found its height above the level of the sea 

 was 549 English feet. This gives us 1/9^- English feet for an 

 alteration of one degree of Fahrenheit in the mean temperature; 

 yet the usual allowance in the Swedish climate has been an altera- 

 tion of 1° of temperature for 260 English feet of elevation. Should 

 we choose to reckon the ten minutes that the south end of the lake 

 Yngen lies farther south than Upsala, as equivalent to an increase of 

 temperature amounting to 0-216 of a degree ; still the temperature 

 of the earth at the lake Yngen would be 1-188° lower than at 

 Upsala, which is a third mere than we were warranted to suppose ; 



* These observation* followed ench other so rapidly in order to observe w hether 

 the heavy fall of snow between the 8th and 10th of October had produced any 

 effect on the springs. The effect was not remarkable. How regularly the tempe- 

 rature of these springs varies will be easily perceived by making the degree* and 

 the time the ordisates and abscissK of a curve. — YVahUnberg. 



