Geological Society, 213 



occurs about 6 feet from the top of the section, and which is not 

 mentioned in Dr. Buckland's paper. This bed was also noticed by 

 Mr. Rofe in many other places in the immediate neighbourhood of 

 Reading, and at Woodley Lodge, about three miles to the east of 

 the town. At the latter locality the order of the beds is as follows : 



Blue clay, about 40 feet. 



The shelly stratum. 



Mottled clay 55 — 



Ditto, occasionally sandy. ... 35 — 



In conclusion, the author states that all the wells in Reading, 

 excepting those supplied by land-springs, both on the north and 

 south of the Kennet, and even within 30 yards of its banks, are 

 regulated by the Thames, rising and falling with that river. This 

 phenomenon, he conceives, may be accounted for, by the Kennet 

 flowing over a bed of tenacious clay, whereas the Thames flows 

 over gravel resting immediately upon chalk, into which the wells 

 are sunk. 



March 12. — A paper was read, entitled, " Observations on the 

 Temple of Serapis at Pozzuoli, near Naples ; with Remarks 

 on certain Causes which may produce Geological Cycles of great 

 Extent. In a Letter to W. H. Fitton, M.D., from Charles Babbage, 

 Esq." 



The author commences this paper with a general description of the 

 present state of the Temple of Serapis, and gives the measurement 

 of the three marble columns which remain standing, and which, 

 from the height of 11 feet to that of 19, are perforated on all sides 

 by the Modiola lithophaga (of Lamarck) ; the shells of that animal 

 remaining in the holes formed by them in the columns. A de- 

 scription is then given of the present state of twenty-seven portions 

 of columns, and other fragments of marble, and also of the several 

 incrustations formed on the walls and columns of the temple. 



The conclusions at which the author arrives are — 



1. That the temple was originally built, at or nearly at the level 

 of the sea, for the convenience of sea-baths, as well as for the use 

 of the hot spring which still exists on the land side of the temple. 



2. That at some subsequent period the ground on which the 

 temple stood subsided slowly and gradually ; the salt water, entering 

 through a channel which connected the temple with the sea, or 

 by infiltration through the sand, mixed itself with the water of the 

 hot spring containing carbonate of lime, and formed a lake of 

 brackish water in the area of the temple, which, as the land sub- 

 sided, became deeper, and formed a dark incrustation. 



The proofs are, that sea-water alone does not produce a similar 

 incrustation ; and that the water of the hot spring alone produces 

 an incrustation of a different kind ; also, that Serpulae are found ad- 

 hering to this dark incrustation ; and that there are lines of imter- 

 level at various heights, from 2*9 feet to 4?'6 feet. 



3. The area of the temple was now filled up to the height 

 of about seven feet with ashes, tufa, or sand, which stopped up the 



