560 PROTECTIOX AOAINST TIATL. 



About 3,500,000 cubic feet of old timber was broken and thrown 

 down, besides great damage done to young wood and to the 

 agricultural crops. Tbe falling of such masses of hail caused 

 the air to rush in all directions, and trees were consequently 

 blown down from all points of the compass. 



According to Claudot("Eev. des E. et F.," 10th March, 1890) 

 French official statistics give 27,000,000 francs as the average 

 value of the annual damage done by hail to French crops in 

 1825-36, whilst in 1884-88, this damage averaged 105,000,000 

 francs, so that insurance rates against hail have increased so 

 as to become sometimes prohibitive. 



Owing to the disastrous effects of hail on agriculture, the 

 question whether the maintenance of woods on mountains 

 and hills affects the prevalence and severity of hailstorms is 

 highly important. It is found that in Canton Aargau, in 

 Switzerland, districts with much woodland suffer less from hail 

 than less wooded districts. 



District. 



Zosingen 

 Lenzburg 

 Muri 



In the northern part of this canton, the hailstorms prevail 

 in the badly wooded tracts, and are scarcely known in the 

 well wooded ones. In Bohemia, however, observation has 

 not supported any connection between woodland and hail. 



3. Protective Measures. 



i. All hill-tops and ridges should be wooded and all l)lanks 

 in forests should be filled with strong transplants. 



ii. Adopt selection fellings in districts subject to hail- 

 storms. 



iii. Mix broadleaved trees with conifers, so that if the 

 latter are seriously injured there may still be left material to 

 restock the woods. 



iv. Seriously injured spruce and Scots pine are ruined and 

 must be felled. With larch and silver-fir recovery is possible. 

 Young broadleaved plants should be cut back and allowed to 

 shoot up again. 



