150 OUTLINES OF FORESTRY. 



assumed, be alternately attracted and repelled into 

 and from the rain-cloud, and thus receive alternate 

 coatings of ice and snow until they finally fell to 

 the ground as hailstones. 



In France, where the reckless destruction of the 

 forest has been attended by a marked increase in 

 the number and severity of hail-storms, miniature 

 lightning-rods have been erected in the fields to 

 prevent the occurrence of hail-storms. These 

 lightning-rods either took the shape of captive 

 balloons secured to the earth by tinsel threads, or 

 of bundles of straw set upright in the field, or of 

 metal rods permanently connected with the ground. 

 Their object was to gradually discharge the air of 

 its free electricity, and thus prevent the occurrence 

 of hail-storms. The name of such rods, paragreles, 

 is significant of their supposed action. Unfortu- 

 nately, they have proved futile in action, since again 

 and again the portions provided with this supposed 

 protection have been as severely visited by hail- 

 storms as unprotected portions. 



An endeavor has been made to explain the 

 peculiar shape of hailstones by the existence of 

 a number of approximately parallel clouds com- 

 posed alternately of snow and rain. Drops of 

 rain falling from the upper cloud would thus 



