Geologica I Society. 2 1 5 



from having been formerly used as such by sea-faring people j 

 that the ground floor of the Aspizio dei Capuccini is now under 

 water ; and that near Pizzo Falcone modern marks are seen on the 

 tufa many inches under the level of the sea at low water. 



Before I quit this branch of the subject, I would wish to suggest 

 to future visitors of this temple, the following topics of inquiry. 



What parts of the building have undergone repair? Can the date 

 of these repairs be deduced from the nature of the materials em- 

 ployed, or the character of the workmanship ? 



Where is the pavement out of level, and to what amount? Are 

 the subsided parts under the lines of thoroughfare, or can their sink- 

 ing be traced to imperfect construction ? Is the foundation such as 

 an architect would call secure? Does it stand on stratum No. 6 of 

 Mr. Babbage's section ? 



Were there roofs to the bath-rooms ? 



Would the fragments No. 6, 7, 8, form one column, or more than 

 one ? Was the original number of large (cipollino) columns greater 

 than four ? 



Is the tufaceous deposit on No. 7 the same as that on the walls? 



Are all the water lines horizontal ? 



Brick-work is found in the strata which buried the temple. What 

 is the character of this brick-work? Is it reticulated? 



Draw up a detailed and exact account of the strata. 



What is the nature of the thermal spring? Evaporate a few 

 gallons of the water, and send the deposit to the Society. 



The plan which accompanies Mr. Babbage's paper being copied 

 from that of Jorio, it is desirable, in order to prevent confusion and 

 save expense, that this plan, with the numbers attached to it, should 

 be adopted in any future description. 



In the concluding part of the paper, Mr. Babbage proceeds to 

 show in what manner existing causes may possibly elevate conti- 

 nents and mountain ranges, and a similar train of reasoning seems to 

 have presented itself to Mr. De la Beche's mind about the same 

 time. The justice, or at least the relevancy of the reasoning, depends 

 on the establishment of many postulates which in the present state 

 of our knowledge can be regarded only as matters of surmise: but 

 I treated this subject so much at large on a former occasion, that I 

 will not detain you with any further observations upon it now. 



A Paper by Dr. Turner, our Secretary, informs us of some expe- 

 riments which have been made on the action of high-pressure steam 

 upon glass, and other siliceous compounds. The glass was suspended 

 within the boiler of a steam-engine, encased in wire gauze at a tem- 

 perature of about 300° commonly for ten hours a day. At the end 

 of four months all the pieces were decomposed, and the plate-glass 

 especially, consisting of silex and soda, was in some pieces corroded 

 entirely through. Window-glass was less acted upon, and rock 

 crystal wholly unaltered. Dr. Turner ascribes these changes to the 

 influence of the water on the alkali of the glass, the white opake 

 matter with which the decomposed pieces were coated being siliceous 

 earth entirely free from alkali ; but some portions of the silex also 



