B. TERRESTRIAL PHYSICS AND METEOROLOGY. 23 



heavy cannonade will effect a similar result. After a careful 

 consideration of the subject, he comes to the conclusion that 

 no human agencies can be relied upon to bring about any 

 material change in the atmosphere with any degree of cer- 

 tainty, although he thinks that large fires, explosions, battles, 

 and earthquakes do tend to cause atmospheric disturbance, 

 and especially to induce a fall of rain, but that for such a re- 

 sult it is necessary that other conditions be suitable, espe- 

 cially that the lower portion of the air contain a great deal 

 of moisture. 12 A.Feb. 16, 307. 



MAXIMA AND MINIMA OF THUNDER-STORMS. 



In a communication upon the annual distribution of thun- 

 der-storms in Austria and Hungary, Dr. Jelinek remarks that 

 from the critical investigations of past years it has been 

 ascertained that in the northern hemisphere there are two 

 minima and two maxima of frequency of such storms. The 

 first minimum occurs in the region north of the polar circle, 

 the second in the region of the trade winds; in both, how- 

 ever, summer storms are rare or entirely wanting. On the 

 other hand, the maxima of frequency of storms occur on the 

 one side in the vicinity of the equator, and on the other side 

 in the temperate zone, and, indeed, they seem to be more fre- 

 quent to the south of Europe. In illustration of this, he re- 

 marks that in Iceland thunder-storms occur almost exclusive- 

 ly in the winter season, and that in the northwest of Scotland 

 the winter storms predominate, although there is sometimes 

 a second maximum in July. The summer storms, on the 

 other hand, are most abundant in Southern and Southwestern 

 Scotland, as well as in France and the rest of Continental 

 Europe. It is considered quite a remarkable fact that Bey- 

 rout has quite a similar distribution of storms throughout 

 the year as Iceland. Thus for ten years, during the four 

 months" of June to September, not one storm was observed, 

 while in winter more than half the entire number for the year 

 occurred, of which one fourth were in January. Again, while 

 the number of these storms at Beirut seems to be very 

 small, they are still fewer at Jerusalem, only eleven having 

 been observed in the space of three and a half years. Sit' 

 zungsber. K. K. Akad,, Vienna. LXI. 



