270 Prof, Bischof oii the Temperature of 



perature with more exactness, than from that single observa- 

 tion. It is to be expected that the yearly variations of the 

 temperature of the soil on this mountain, the height of which 

 is equal to that of the limits of perennial snow in the Alps, are 

 enclosed within narrower bounds than in the valleys. The 

 temperature at the depth of four feet, will no doubt, at this 

 height, fall in winter below 32°. If, therefore, the water in 

 the bottle should have frozen during last winter and broken 

 the bottle, it would be a sign that the temperature had really 

 sunk considerably below 82°. Besides the three points where 

 Mr Ziegler has observed the temperature of the soil since Sep- 

 tember 1835 (Chap. XVII. p. 160.), he chose two others in April 

 1836 for the same object. The one is near the bridge over the 

 Muhlbach, on the usual road to the Great Scheideck, about a 

 quarter of a league from the parsonage-house ; the other is near 

 the highest winter habitation in the whole valley, about half a 

 league further up. The former may be about equally distant 

 from the extremities of the two glaciers ; the latter is situated 

 somewhat nearer to the upper glacier. Their heights Mr 

 Ziegler estimates at about 300 and 700 feet above the church 

 at Grindelwald, but he will endeavour to ascertain it by baro- 

 metrical measurements. So that we shall Avithin a year receive 

 a series of observations from the environs of Grindelwald, which 

 will sufficiently explain to us the extraordinary thermometrical 

 relations of that neighbourhood. If we also succeed in obtain- 

 ing an approximative value for the mean temperature on the 

 FauHiorn, we shall know the decrease of temperature from 

 Grindelwald, 3237 feet* above the sea, to the summit of this 

 steep mountain, which reaches the limits of perpetual snow.-f- 



" According to Michaelis, 3265 feet. Frobel und Heer, loco cit. 2C2. 



+ But even these observations will not be sufficient to lead to any general 

 conclusions whicli would obtain at least for the temperate zones, 'the de- 

 sired end can only be attained by observing in various latitudes and under 

 quite different climatic and local circumstances. I have reason to hope that 

 observations on the decrease of temperature in the soil will be undertaken at 

 other places in the Alps, in various mountainous districts of Germany, in 

 Sweden, and even in the Carpathian mountains. At some places they are 

 already in progress. Observations in the Carpathian mountains will perhaps 

 decide the question, whether the decrease of temperature is there less rapid, 

 as no perpetual snow is found on them, although their height is such that it 

 might be expected to be found there. Still more interesting would be obser. 

 valions on the Himalaya mountains, where the height of the limits of perpe- 

 tual snow present so great an anomaly ; V. Humboldt supposes it on the 



