172 Mr. Charles Tomlinson on 



twigs and leaves. Nevertheless, hail was known to be of 

 frequent occurrence in well- wooded localities, also in towns 

 where lightning-conductors were common. In spite of this, 

 vast numbers of poles, with or without metal wires, were 

 erected at great cost in fields and vineyards in various parts 

 of Europe ; and in 1820 an ignorant apothecary recommended 

 pillars of straw as being excellent paragreles, and they, too, 

 were extensively adopted . Well may Becquerel denounce the 

 paragrele as " cette invention de l'ignorance dont la science et 

 le bon sens public ont deja fait justice " ! 



Other methods of guarding against hail have been recom- 

 mended and adopted, such as making fires on the ground on 

 the approach of a storm, discharging artillery and otherwise 

 exploding gunpowder ; but these methods must be classed 

 among the inventions of ignorance, although so good an 

 observer as Matteucci u refers to a village in Italy where the 

 peasants, acting under the advice of the Cure, place, at 

 intervals of about 50 feet, heaps of stones and brushwood, and 

 set fire to the latter when a storm is seen to be approaching. 

 The plan had only been adopted three years when Matteucci 

 made his report, and that is too short a time to base any con- 

 clusion on ; but it has been suggested that, while hail does 

 great damage in the outskirts of London, it is less harmful in 

 the denser part of the metropolis, probably on account of the 

 vast column of heated air that rises from it altering the local 

 atmospheric conditions required for the production of large 

 hail.- 



The occurrence of hail in hot weather, often at the hottest 

 part of the day, sometimes in the form of masses of ice of con- 

 siderable size, apparently from a cloud situate far below the 

 snow-line, is a problem that has often appealed to the scientific 

 ingenuity of physicists for solution. As already remarked, the 

 accompanying electrical displays naturally led to an electrical 

 theory, of which Muschenbroek 12 was the original parent. 

 He was succeeded, amongst others, by Mongez 13 , Muncke 14 , 

 De Luc 15 , Lichtenberg 16 , Lampadius 17 , and lastly by Volta 18 . 

 Now, as the inventor of the pile and of the electrophorus took 

 higher rank as an electrician than the others just named 

 (whose hypotheses he doubtless had examined), it will be 



11 Arago, Meteorological Essays, Sar la Grele. 



12 Introduction. ]3 Journal de Physique, vii. p. 202. 

 14 Gehler's Worterhuch, v. p. 54. 15 Idees, ii. sec. iii. chap. 2. 



16 Schriften, viii. p. 85. l7 Atmospharol, p. 153. 



13 Sopra la Grandine, Opere, i. part ii. p. 353. 



