Connection ivith the Climate of Berlin. 157 



But with this circumstance there is a question connected, which 

 affects us closely. It is this, Can we hope to discover a stationary 

 point amidst this eternal change ? Is there, in the closely-associated 

 chain of causes and effects, any prospect of our being able to dis- 

 tinguish between the settled and the variable ? Our older meteoro- 

 logists thought so ; for they described the temperature of a place by 

 giving the highest degree of its observed warmth and cold. They 

 were of the opinion that nature does not lawlessly deviate from cer- 

 tain rules, and that she remains conscientiously between the two ex- 

 tremes which limit her regularity. And they were right ; for at a 

 moderate depth below the surface of the earth we find that invari- 

 able degree of warmth which we fix upon as the mean tempera- 

 ture of the place of observation. Thus, at the depth of 30 inches, 

 there is no difference between day and night ; at 30 to 35 feet the 

 difference between summer and winter disappears. So slowly, in- 

 deed, does the warmth of the atmosphere penetrate into the soil, 

 that at the depth of 3 feet the warmest day is the 22d of August ; 

 at 6 feet, the 30th of August ; at 12 feet, the 9th of October ; and 

 at 24 feet, the 15th of December, whilst at that depth the greatest 

 cold falls here on the 13th of June. Springs which rise from this 

 depth preserve the same temperature all the year through ; thus the 

 one on the road from Potsdam to Templin stands at 50° F. the 

 same as that of the Lomsenbrunnen at Berlin. How surprised the 

 skater must be, when he finds the places where the springs rise in 

 the ponds are not frozen over in winter, though they are the very 

 spots which he had avoided in summer, whilst bathing, on account 

 of their cold. So little power has the stratum in which the life of 

 the earth pulsates in higher latitudes, that the ground which still 

 bears on its surface woods of pine and fir trees, is, even during the 

 summer, frozen so hard at a very moderate depth, that in the year 

 1821 on Menzikoff's grave being opened at Beresoff, the lines of 

 sorrow might still be traced on the features of the banished exile, 

 whose heart had ceased to beat for more than a century. 



If we can imagine this variable stratum removed from the earth, 

 we should obtain on the new surface the simple representation of a 

 climate of mean temperature; of that temperature which every place 

 would shew if its thermometer stood always at the same height. 

 In this way we should find that in Berlin it would stand every day 

 at 48°*875 Fahr. that in Hindostan there are places where the mean 

 temperature would be 81°'5 Fahr. ; that Parry, on the contrary, 

 would fix his winter quarters in a place where the mean temperature 

 would sink to — 2° Fahr., or 34° below the freezing point. This varia- 

 tion, however, does not entirely depend on distances from the pole, for 

 places situated in the same degree of latitude are much warmer on the 

 western than on eastern coasts. Scotland, Denmark, and Poland, 

 have climates of equal warmth. Ireland, England, Belgium, and 

 Hungary, enjoy the mean temperature which would characterise a 

 Naples lying on the east coast of Asia. In America we find the 



