Hot and Thermal Springs. \Q\ 



10th of November, as was the case in my observations near Bonn^ 

 communicated in Chap. XVIII., we might by interpolation in 

 the above observations obtain a mean for each of the three points, 

 which would be as follows : — 



Glacier. Mettenberg. Garden. 



34°.90. 40».28. 44°.84.* 



But should they fall, according to my observation on the Lo- 

 wenburg, on the 24th November, the interpolation would give 

 for the mean temperatures — 



At the Glacier. Mettenberg. In Garden. 



33=.91. 38°.30. 42".68.* 



In the former case the increase of the mean temperature from 

 the glacier to the foot of the Mettenberg, would be 37°.37 ; and 

 from thence to Grindelwald 36°.5(); in all 41°.94. In the lat- 

 ter case the increase would be, from the first to the second point, 

 4".39, and from the second to the third, 4°.S95 making in all 

 8°.78. Taking the mean of these two results, we find that the 

 increase of temperature from the glacier to Grindelwald, a dis- 

 tance of about 4500 feet, is 9''.36. If, then, the increase of tem- 

 perature towards the interior of the earth, advances 2°.25 in 115 

 feet at the glacier; the chthonisothermal of 43o.77, which, at 

 Grindehoald, touches the surface, will pass at a depth of 478 feet 

 under that point of the glacier, and the chthonisothermal of 

 39°29, which touches the surface at the foot of the Mettenberg, 

 will dip 250 below the same point. As the second point of 

 observation, at the foot of the Mettenberg, is situated about 1800 

 feet, and the third at Grindelwald, about 4500 feet distant from 

 the glacier ; and as, farther, the two first places are nearly on 

 the same level, but Grindelwald 248 feet higher than the lower 

 end of the glacier ; those chthonisothermals must form an angle 

 with the horizon of about 9°.10' to 10°.27. 



These relations are illustrated in the diagram. Fig. 5, Plate 2, 

 where c is the point of observation of the glacier, d the point of 



* Hear found the mean temperature of the air at Afatt, in the canton Gla- 

 rtM, 2500 feet above the level of the sea, between August 1831 and August 

 18.S2, to be 4:r.85. (Frobel and Hecr, Mittheilungen aus dem Gebiete der 

 theoret Erdkunde. Zurich. 1830. P. 492.) As Grbulehvald I' es V>n feet 

 higher than Mall, and in the vicinity of the glacier, 42°.G8 is probably near- 

 er the truth than 44°.84- 



VOL. XXIV. NO. XLVH. — JAXUARY 1838. I. 



