Mr Murray on the Paragrele or Protector from Hail, 105 



Pinnazzi of Mantua proposed, as early as 1788, the erection 

 of numerous metallic points in the fields, for the purpose of de- 

 priving the clouds of their electricity, and thus preventing their 

 resolution into hail. Many S9avans entertained the proposal as 

 exceedingly plausible, especially those of the academies of Dijon 

 and Arras, and called to recollection what had been previously 

 stated by Guinard, Buissant, Morveau, Berthollet, and more 

 recently by Bosc and Le Normand. A few years ago, Mons. 

 L'Apostolle of Geneva endeavoured to modify the erection of 

 Pinazzi by the substitution of straw ropes, but experience 

 proved them inefficient. The paragreles of L'^Apostolle had 

 fallen into discredit and oblivion, when, in 1821, Mons. Thol- 

 lard, Professor of Natural Philosophy in the College of Tarbes 

 in France, in the department of the High Pyrenees, revived 

 them with some modifications. His proposal was to erect poles 

 of willow, poplar, pine, chesnut, or other trees, armed with 

 sharpened brass points, attached to a rope formed of ripe bar- 

 ley or rye-straw, and raw-thread twisted throughout its extent. 

 He contended that he had thus succeeded in securing a territory 

 of ten communes. This assurance had considerable effect, and 

 excited general attention. The French journals took the lead 

 in the discussion ; some spoke favourably, and others unfavour- 

 ably, of the project. The Italians, on their side, did not keep 

 silent on a subject so important to their interests ; and the theo- 

 ry of the paragreles has been attacked and defended in France, 

 Italy and Switz3rland. 



Such is a succinct account of the history of the paragreles, so 

 far as I was able to obtain it. The inferences deduced theore- 

 tically from conducting rods are all in favour of them. The for- 

 mation of hail is a well known electric phenomenon, and con- 

 ductors of electricity are influential in changing the electric cha- 

 racter, or modifying the quantity of electricity. By paragreles 

 the hail or fragments of ice are softened into snow or melted in- 

 to rain. The results obtained all demonstrate their value and 

 importance. From the moment I witnessed them I unhesita- 

 tingly pronounced a verdict in their favour. Mons. Crud has 

 the merit .of having established them in the Bolognaise terri- 

 tory ; Professor Chavannes in the Canton de Vaud (who met 

 with considerable opposition and hostility) ; and Beltrami in 

 Lombardy. 



