14 8 ConjeSlures refpeGing the Origin 6f Stonet 



Note — i". Hence we fee that looo inches or meaf'iircs of 

 dry air at 32' would become ioo4"4675 at 34*25 Fahr. and 

 at 50° wouid Ijecome 1017-87. Hence 1000 meafiires o{ dry 

 air gain "9^5555, &c. by each degree of Fabr. above 32" 

 (orniorc compendiduOy i"9856, which is true to two decimal 

 places) or nearly two- 



ado. We fee the fotirce of the difcordant refults of 

 D'Amonlons, De Luc, Lambert, Schuckburgh, Roy, Ber- 

 thollet, and Monge, &c. ; for they all operated upon air more 

 impregnated with various degrees of moillure; befides taking 

 tlie boiling point at difl'erent barometrical heiohts; in the 

 prefcnt experiments it was taken at 29*841 Englifh inches. 



3tio. It appears that the expanfions are as the diflerences of 

 heat above 32', as D'Aniontons, Lambert and Schuckburgh 

 alfo noticed^ though their experiments, not being made on 

 perfectly dry air, could not be very exadl. 

 [To be continued.] 



XXIV. Some ConjeSInres reJpeEl'irg the Origin of Stones 

 which have been obfcrved to fall from the Clouds, By 

 William Beauford, A.M.* 



T 



H E fiilling of ftones from the clouds, a natural phreno- 

 menon not generally undcrllood, is by no means a novel cir- 

 cumftance in the hidory of nature. Several ftones were ob- 

 ferved to fall from the clouds in Yorkfliire in T360, in Bohe- 

 mia and Saxony in 1480, in Bohemia about 1753, ^" ^'^' 

 enna in 1794, in Portugal in 1796', in Yorkfhire in England 

 in 1795, and near Benares in theEaft Indies in 1798. From 

 an anaiyfis made of thcfe Itones by the French academicians 

 in 176'S, and by the Royal Society of London in 1802, they 

 are all found liniilar in their component parts to each other, 

 but difliinilar to all bodies found in mines and quarries, being 

 Goinpulcd principally of four kinds of fubdances : the firli 

 being in the forui of dark grains, compofed of iilex, mag- 

 nefia, iron, and nickel ; the fecond, a kind of pyrites; the 

 third, metallic iron ; and the fourth, a gray earthy fubdance 

 which ferves as a cement to the others, and with which they 

 were coated. From thefe compofitions the matter feems to 

 be of volcanic origin ; yet it is difficult to conceive how ftones 

 of any confiderablc magnitude could be thrown at fuch a di- 

 ftance from any volcano as thole found in Bohemia, Saxony, 

 and Britain. The neareR volcatios to Britain are thofe of 

 Vefuvius, JEtna, and HecUi: a (lone to be thrown into Bri- 



■ Coiiiiiiunicited by the Author. 



taia 



