connection with the Climate of Berlin. 1()I 



But how do clouds of snow and rain originate over our plains, 

 which are situated far from the cooling summits of the mountains ? 



A celebrated amateur gathered together a large assembly in the 

 council-hall of a northern residence. It was one of those icy star- 

 bright nights which are so aptly called iron nights in Sweden. In 

 the saloon, however, there was a fearful crowd, and the heat was so 

 great that several ladies fainted in consequence. An officer tried to end 

 this distressing state of things by attempting to open a window. But 

 it was impossible, so fast it was frozen to the window cill. Like a 

 second Alexander he cut the Gordian knot by breaking a pane of 

 glass, and now, what happened ? It snowed in the room. Circum- 

 stances so favourable as these seldom present themselves for obser- 

 vation here. But I have, even in Berlin, seen a thick mist, form 

 itself at a private ball, when, on one occasion, the doors opening 

 upon the balcony were thrown open for a moment. Thus, wherever 

 warm air becomes mixed with cold and moist air, a precipitation 

 takes place. This is the reason why an eternal mist overclouds the 

 sea of Okotsk, where the warmth so sensibly declines towards the 

 north, that, on the same neck of land, shapeless sea-horses, the in- 

 habitants of the polar seas, and elegant certhiadse, the feathered mes- 

 sengers of the south, meet together. It is the same phenomena on 

 a smaller scale which one sees at St Petersburg, at the magnificent 

 festivals given in the winter palace, when a continual condensation 

 is always taking place in the outer apartments. In order, therefore, 

 to understand our weather, we must seek out the principles on which 

 such mixture of unequally warmed air takes place ; but to do this 

 I must somewhat enlarge, whilst choosing for my guides two of the 

 learned men of the present day, about whom geology, geography, 

 and meteorology dispute as their heroes, each of the three sciences 

 wishing to claim the two philosophers for itself. 



If we open a door leading from an outer passage into a warm 

 room, a double draught of air takes place, the cold air streaming in 

 below, and the warm air flowing out above. This may easily be 

 proved by the flame of a candle. Placed on the ground it is wafted 

 towards the room, held half-way up it stands upright, above it is 

 wafted towards the outer air. On the earth the polar regions repre- 

 sent the outer passage, and the torrid zone represents the warm 

 chamber. There are two cold zones and one torrid, that is to say, 

 a warm room between two cold passages, the doors between the two 

 are always open, the room is always heated to a very high tempera- 

 ture, and there is a constant draught of air, which is called the 

 " trade-winds." "Where both currents of air meet, is a region of 

 calms, and it is so named. As, however, the apparent course of the 

 sun varies between the tropics, the region of calms does not always 

 remain in the same place, but follows the sun, and the whole pheno- 

 mena of trade-winds follow in its train. Where the trade-winds pre- 

 vail, the sky is perfectly cloudless, because flowing towards warmer 



VOL. LIV. NO. CVII. — JANUARY 1853. L 



