95 



\ 



cities, but may be inferred from ancient authors, and especially 

 from some remarks of Aristotle, who states that Babylon was 

 rather " a community than a city" like the Peloponnesus. If we 

 confine the city to the limits assigned by Diodorus, it will not in- 

 clude all the existing remains; whereas the limits assigned by He- 

 rodotus include all those venerable ruins in the vicinity of Hillah, 

 that still astonish us by their stupendous dimensions. 



2. On the Expansibility of different kinds of Stone. By 

 Mr Alex. J. Adie, Civil Engineer. 



This paper contains the results of an extensive series of experi- 

 ments made upon diflFerent kinds of stone, as well as upon iron and 

 upon brick, porcelain, and other artificial substances. The instru- 

 ment employed was a pyrometer, of a simple construction, capable 

 of determining quantities not greater than ~^ of an inch. The 

 length of the substances generally employed was 23 inches. The 

 general result of these experiments is, that the ordinary building 

 materials of stone expand but very little differently from cast-iron, 

 and that, consequently, the mixture of those materials in edifices is 

 not injurious to their durability. The experiments from which the 

 expansibility of the substances was numerically determined, were 

 made between the limits of ordinary atmospheric temperature and 

 that of 212° ; steam being introduced for that purpose between 

 the double casing of the instrument. 



The following results were obtained for the fractional expansion 

 of the length, for a change of temperature of 180° Fahr. : — 



Table of the Expansion of Stone, Sfc. 



1. 



2^ 



3. 



4. 



5. 



6. 



7. 



8. 



9. 

 10. 

 11. 

 12. 

 13. 

 14. 

 15. 



la 



17. 



Roman Cement, 



Sicilian White Marble, 



Carrara Marble, 



Sandstone from the Liver Rock of Craigleith Quarry, 

 Cast-iron from a rod cut from a bar cast 2 inches square, 

 Cast-iron from a rod cast half an inch square. 

 Slate from Penrhvn Quarry, Wales, 

 Peterhead Red Granite, 



Arbroath Pavement, 



Caithness Pavement, 



Greenstone from Ratho, 



Aberdeen Gray Granite, 



Best Stock Brick, 



Fire Brick, 



Stalk of a Dutch Tobacco-pipe, 



Round rod of Wedgewood Ware (11 inches long). 



Black Marble from Gal way, Ireland, 



Decimal of length 

 for 180P Fahr. 



.0014340 



.00110411 



.000653» 



.0011743 



.00114676 



.001102166 



.0010376 



.0008968 



.0008980 



.0008947 



.0008089 



.000/8943 



.0005502 



.0004928 



.0004573 



.00045294 



•00044519 



