432 DOMAIN V. CALCAREOUS. 



smaller ova of fishes. They split in the cutting 

 of the stone ; so that it is capable of being 

 brought to a surface, very smooth and equal. 

 Besides, this and all like sorts of stone that are 

 composed of granules, will cut and rive in any 

 direction: as well in a perpendicular, or in a 

 diagonal, as horizontally and parallel to the site 

 of the strata. 'Tis for this reason that they have 

 obtained the name of freestone. Then these 

 bear the injuries of the weather equally and in- 

 differently in all positions : whereas all the stone 

 that is slaty, with a texture long, and parallel to 

 the site of the stratum, will split only length- 

 ways, or horizontally; and if placed in any 

 other position, 'tis apt to give way, start, and 

 burst, when any considerable weight is laid- 

 upon it. Which inconvenience the Portland 

 stone being not liable to, cutting freely, and 

 being of a colour very good and agreeable, 'tis 

 made use of for the better buildings and works 

 about London."* 



Da Costa calls the Portland stone an alkaline 

 sandstone; and, with equal error, adds that 

 sandstones have obtained the name of freestones 

 because they were cut in any direction. He 

 subjoins some account of the Surry stone of 



* Woodward's English Fossils, 1729, i. 17* 



