32 On the Heat of Springs, [July, 



Here also the mean has become higher, in proportion as the 

 scale of variations nas diminished. In other respects this last spring 

 differs from the two preceding in the greater length of time during 

 which it remains at its highest temperature, and likewise in the 

 long period during which its lowest temperature continues. The 

 temperature curves of all these springs show that the deeper springs 

 have a higher mean temperature ; and it follows, as a consequence, 

 that the heat of summer penetrates farther into the earth than the 

 cold of winter. 



These observations show that all springs are coldest at the end of 

 spring, and hottest, on the contrary, in harvest : but the variable 

 springs reach their highest temperature about the end of August, a 

 short time after the temperature of the air has arrived at its maxi- 

 mum : but the constant springs reach their highest temperature in 

 September. From this it follows that the nature of such springs 

 may be determined from a few observations made at these seasons 

 of the year. The following observations, though made only a few 

 times during the course of the year, make us acquainted with every 

 thing requisite to be known respecting the springs examined. 



There is a spring at Gnesta-lVvndmuhle, on the road to Fundbo, 

 which rises directly out of a sand hillock, and in such abundance 

 that it immediately forms a rivulet. Next to the Sandviks spring, 

 it may be considered as the greatest in all that tract of country. 

 This spring gave the following temperatures: — 



Gnesta quarn kalla, 1810—13 May 42-53° 



26 August 42-80 



26 > September 43-16 



2/ October 43-43 



The mean temperature of this nearly permanent spring appears 

 to agree pretty well with that of the preceding. 



A spring at the rivulet below Norlijgard, in the parish of Bond- 

 kyrka, in a clay soil : — 



1S09— 24 December 42'9S° 1S10— 1 May.... 42-SO 



1810— 24 Januarv.. 42-98 25 4_>-80 



27 42-9S 10 June 42-80 



22 February. 42*80 25 August .. 42-98 



31 March .. 42-80 2/ September 43-34 



Not far from this, and near Korlyland, well known to the 

 botanists of Upsala, lies the spring of Xuilylaiul. 



1810—25 May 42-i?0° 



1 September 43-34 



27 43-88 



At Mysbvgard, in the parish of Danmark, there is a spring 

 which rises from a flat bottom with such vio'enee that it forces up 

 the gravel half a foot high in the water. It is one of the most 

 constant springs. It gave — 



