AQUEOUS ATMOSPHERIC PHENOMENA. 



475 



from the first of which the annexed representation is taken. Upon examining some snow 

 which fell at Yverdon in Switzerland, in 1829 and 1830, M. Huber Burnand found 

 its crystals to consist of stellar plates with six rays, along each of which filaments were 



Various forms of Snow Crystals. 



disposed after the form of feathers, and these also had finer filaments similarly arranged. 

 He observed that in the former year almost everyday the crystals presented a new variety 



Various forms of Snow Crystals. 



of shape, sometimes resembling parallel fillets, leaves, and spines, with a rosette termi 

 nation. 



It is rarely that snow is seen in the northern hemisphere below latitude 30 in 

 America, and 36 in the eastern world, the latitude of Algiers, and for some distance 

 above those limits its appearance is very infrequent and brief, except in the upland 

 regions. During the severe winter of 1830, when there was an average depth of six feet 

 of snow in Denmark, and it accumulated on the low grounds of Wiltshire in some places 

 to the depth of fifteen or sixteen feet, the crest of Vesuvius, in latitude 41, was covered 

 with it for the space of ten days a most unusual occurrence. A fall of snow occasion 

 ally intrudes into our summer, but seldom in any quantity, though Kent and Sussex have 

 been wrapped in this garb of winter in the month of June. It has also visited low levels 

 within the limits of the torrid zone, as at Canton, in latitude 23, in February 1836. 

 The following letter, which appeared in one of the public journals, contains an inter 

 esting account of this event, which may not be repeated for many generations: "I 

 write you under the inspiration of a most unprecedented meteorological event the phe 

 nomenon of a very heavy fall of snow in Canton. I woke an hour and a half ago, and 

 could not believe my eyesight. Huge and thick flakes of real snow, and not white 

 paper, summoned me from my warm bed ; and on looking out, sure enough the whole 

 scene was 'winter in its roughest mood,' the snow on every house-top two, three, and 

 four inches deep, and in the corners and ridges of course much more. The thermometer 

 in our southern verandah was then standing at 37. There was a light air from the 

 north, in which direction the wind has been without intermission for three days past, 

 sometimes blowing hard. Five or six days ago the wind was from the S.E., a most 

 unusual occurrence in this monsoon ; and the weather was so mild then, that we break 

 fasted with open windows ; and a water excursion in the evening was by no means 

 unpleasant, even to the idle steersmen in the wherry. But though the change was rapid, 

 and the cold all yesterday very intense, no one predicated the length it would go. The 

 thermometer was yesterday 47 in the morning, and rose to 51 and 52 during the day. 

 The astonishment and mirth among the Chinese, not one of whom about us has ever 

 beheld snow before, is unbounded ; and the elders of our European society are at this 

 moment in the ecstasy of revived associations, pelting each other with snow-balls from 



