Curiosities of S"iercr. ' 59 



warm air of the room had sustained an amount of moisture in 

 a transparent condition which it was not able to maintain, 

 when mixed with the colder air from without. The vapour 

 was first condensed, and then frozen. 



ABSENCE OF SNOW IN SIBERIA. 



There is in Siberia, M. Ermann informs us, an entire district 

 in which during the winter the sky is constantly clear, and 

 where a single particle of snow never falls. Arago. 



ACCURACY OF THE CHINESE AS OBSERVERS. 



The beautiful forms of snow-crystals have long since at- 

 tracted Chinese observers ; for from a remote period there has 

 been met with in their conversation and books an axiomatic 

 expres ion, to the effect that "snow- flakes are hexagonal," 

 showing the Chinese to be accurate observers of nature. 



PROTECTION AGAINST HAIL AND STORMS. 



Arago relates, that when, in 1847, two small agricultural 

 districts of Bourgoyne had lost by Hail crops to the value of 

 a million and a half of francs, certain of the proprietors went 

 to consult him on the means of protecting them from like 

 disasters. Resting on the hypothesis of the electric origin of 

 hail, Arago suggested the discharge of the electricity of the 

 clouds by means of balloons communicating by a metallic wire 

 with the soil. This project was not carried out ; but Arago 

 persisted in believing in the effectiveness of the method pro- 



Arago, in his Meteorological Esaays, inquires whether the firing of 

 cannon can dissipate storms. He cites several cases in its favour, and 

 others which seem to oppose it ; but he concludes by recommending it 

 to his successors. Whilst Arago was propounding these questions, a 

 person not conversant with science, the poet Me'ry, was collecting facts 

 supporting the view, which he has published in his Paris Futur. His 

 attention was attracted to the firing of cannon to dissipate storms in 

 1828, whilst an assistant in the " Ecole de Tir" at Vincennes. Having 

 observed that there was never any rain in the morning of the exercise 

 of firing, lie waited to examine military records, and found there, as he 

 says, facts which justified the expressions of " Le soleil d'Austerlitz," 

 " Le soleil de juillet," upon the morning of the Revolution of July-; and 

 he concluded by proposing to construct around Paris twelve towers of 

 great he ght, which he calls "tours imbrifuges," each carrying 100 can- 

 nons, which should be discharged into the air on the approach of a 

 storm. About this time an incident occurred which in nowise confirmed 

 the truth of M. Mery's theory The 14th of August was a fine day. On 

 the 15th, the fdte of the Empire, the sun shone out, the canron thun- 

 dered all day long, fireworks and illuminations were Mazing from nine 

 o'clock in the evening. Every thing conspired to verify the hypothesis 

 of M. Mery, and chase away storms for a long time. But towards 



