74 



ferent ilistances beneath the uppermost or water-level line; — that 

 several fragments of columns are perforated at the ends. 



5. The land continuing to subside, the accumulations at the 

 bottom of the temj>]e were submerged, and Modiolse attaching 

 themselves to the columns and fragments of marble, pierced them 

 in all directions. The subsidence continued until the pavement of 

 the temple was at least nineteen feet below the level of the sea. 



The proofs are derived from the condition of the columns and 

 fragments. 



6. Tlie ground on which the temple stood appears now to have 

 been stationary for some time, but it then began to rise. A fresh 

 deposition, of tufa or of sand, was lodged, for the third time, within 

 its area, — leaving only the upper part of three large columns visible 

 above it. 



Whether this took place before or subsequently to the rise of 

 the temple to its present level, does not appear; but the pave- 

 ment of the area is at present level with the waters of the Mediter- 

 ranean. 



The author then states several fads, which prove that consi- 

 derable alterations in the relative level of the land and sea have 

 taken place in the immediate vicinity. An ancient sea-beach ex- 

 ists near Monte Nuovo, two feet above the present beach of the 

 Mediterranean ; — the broken columns of the Temples of the Nymphs 

 and of Neptune, remain at present standing in the sea ; — a line of 

 perforations of Modiolae, and other indications of a water-level 4 

 feet above the present sea, is observable on the sixth pier of the 

 bridge of Caligula; and again on the twelfth pier, at the height of 

 JO feet ; — a line of perforations by Modiolse is visible in a cliff op- 

 posite the island of Nisida, 2.2 feet above the present level of the 

 Mediterranean. 



The author considers the preceding inferences as a legitimate 

 induction from the observed and recorded facts; and proceeds 

 to suggest an explanation of the gradual sinking and subsequent 

 elevation of the ground on which the temple stands. From some 

 experiments of Col. Totten, recorded in Silliman's Journal, he has 

 calculated a table of the expansion, in feet and decimal parts, of 

 granite, marble, and sandstone, of various thicknesses, from 1 to 

 500 miles, and produced by variations of temperature of 1°, 20°, 

 50°, 100°, 500° of Fahrenheit : and he finds from this table, that if 

 the strata below the temple expand equally with sandstone, and 

 a thickness of five miles were to receive an accession of heat 

 equal only to 100°, the temple would be raised 25 feet; — a greater 

 alteration of level than is required to account for the phenomena 

 in question. An additional temperature of 50° would produce the 

 same effect upon a thickness often miles; and an addition of 500° 

 would produce it on a bed only a single mile in thickness. 



Mr. Babbage then adverts to the various sources of volcanic 

 heat in the immediate neighbourhood : and he conceives that the 

 change of level may be accounted for by supposing the temple to 



