1£6 



History of Ike Sarsens. 



In the gravels and brick-earths of Surrey, Berks, and Wilts 

 water-worn Sarsens and more or less rounded fragments are of fre- 

 quent occurrence. Some of the more usual sizes are : — 



Length. 



Breadth. 



Thickness. 



Indies. 



Inches. 



Inches. 



23 



19 



15 



23 



24 



7 



17 



8 



10 



III. — Constitution of the Sarsens. 



In their composition the Sarsens are sandy, — in fact they consist 

 of quartz sand, either fine or coarse (grit), sometimes with pebbles 

 and angular bits of flint in greater or less quantities. As to their 

 structure, their internal appearance very roughly resembles, in most 

 cases, that of broken loaf-sugar ; hence it is said to be " saccharoid " 

 or " saecharoidal " ; sometimes they are more closely crystalline. 

 In the middle they are dense and hard, the sand-grains being close- 

 set and strongly cemented with silica (the same natural substance 

 as the quartz and flint) . The sand has been derived from very old 

 rocks containing or made of quartz ; such as granite, quartzites, and 

 quartz- veins in schists. The first-named is the most likely source ; 

 and, while the quartz-grains remained, after its degradation, to form 

 sand-beds, and the mica was floated away to a distance, the de- 

 composed felspar yielded the kaolin to form the clay-beds associated 

 with the sands of the Tertiary formations, and free silica also 

 sufficient in some instances to cement the sands into blocks, if not 

 as whole beds. The flint pebbles have been derived from the Chalk. 



On their surfaces they are often soft and friable : the sand-grains 

 either not having been closely cemented, or having lost their holding 

 power. The sand itself is white and pellucid, or colourless ; but it 

 is stained 1 very generally with iron-oxide or natural iron-rust. 

 Hence the stones very often have an irony, rusty, or ferruginous 

 colour of more or less intensity ; and the outer part is frequently 



1 Noted also by Mr. W. Cunnington, as quoted by Mr. W. Long, Wilts Mag. , 

 vol. x., pp. 71—74. 



