200 DESTRUCTION OF POMPEII. 



and finally, he states, *' two entire cities, Hercula- 

 neum and Pompeii, were buried under showers of 

 ashes, while all the people were sitting in the 

 theatre." 



Mr. Lyell thinks that there is no evidence to prove 

 that any lava flowed from Vesuvius in 79, and that 

 the ejected substances which overwhelmed Pompeii 

 were lapilh, sand, and fragments of molten lava, as 

 when Monte Nuovo was thrown up in 1538. From 

 the excavations which have been made, it is certain 

 that none of the inhabitants perished in the theatres, 

 and that but verj^ few perished at all. 



It appears, from an examination made by Mr. 

 Lyell in 1828, that the city of Pompeii was covered 

 with numerous alternations of different horizontal 

 beds of tuff and lapilli,* for the most part thin, and 

 subdivided into very thin layers. 



The following is a section : 



Fig. 43. 



r Ft. In. 



^ ^^^^^^^^^ jBlack ^sparkling sand - - 0 3 



2 iVegetable mould - - - 3 0 



S illllllllllllllllllllllllll!lllll!l||||l|lli :Br^^ incoherent tuff --^16 

 4 ^^^^^^^^. |Small scoriae and white lapilh* - OS 

 S : jBrown earthy tuff - - - 0 9 



e ^^^^ l Do. with lapilh in layers - 4 0 

 'i mmmmm^j Layer of whitish lapilli -.01 

 ^■llllllllllllllllllllllllllllllllliijGrav solid tuff - - - 0 3 



S — j Pumice and white lapilli - - 0 3 



The depth of the bed of ashes above the houses 

 is variable, but seldom exceeds 12 or 14 feet. Nos. 



3 and 5 of the above strata were filled with small 

 prismatic globules. Mr. Scrope saw these formed 

 in great numbers in 1822, by rain falling during a 

 volcanic eruption on fine volcanic sand ; and he also 

 states that they are produced like hail in the air, by 

 the mutual attraction of the finest particles of damp 



* Small volcanic cinders, little stones. 



