By William Gowland, F.S.A., F.I.C. 



57 



evidently been selected for the work in which they were employed 

 owing to their great hardness and toughness. 



The chief features of the rock of these several mauls are as 

 follows : — 



1 is a very fine-grained rock of great hardness. The cement between the 

 grains is so tough that many of the quartz particles are broken across in the 

 fractured surface, giving rise to a peculiar lustre. Under the microscope the 

 rock is seen to be made up of quartz-grains, mostly sub-angular, with some 

 partially decomposed felspar and black magnetite (?), the whole evidently 

 derived from crystalline rocks (granite, etc.). The siliceous cement between 

 the grains is almost entirely crystalline. 



2 is very similar to the last, but with some coarser grains. The siliceous 

 cement between the grains, however, is less perfectly crystallized, and under 

 the microscope with polarized light, resembles the polysynthetic quartz in 

 cataclastic rocks. 



3 is similar to 2, with the exception that the siliceous cement between the 

 sand-grains is still less perfectly crystallized and is almost chalcedonic in 

 character. 



4 is almost identical in character with 2, consisting of grains of sand of 

 very unequal size. 



5 is much coarser in grain than any of the preceding varities, and the 

 siliceous cement between the large sand-grains is of a perfectly chalcedonic 

 character. 



6 is very similar to the last, being rather coarse-grained, but with the 

 chalcedonic cement assuming a somewhat radiated structure around the 

 sand-grains. 



7 is a fine-grained rock, very similar to No. 1 in the size and character of 

 the sand-grains, but the cement is chalcedonic rather than perfectly crystalline. 



8 is a much coarser-grained variety with a chalcedonic cement. In 6 and 

 8 the radiated fibrous quartz crystals give an appearance resembling that of 

 the well-known Ightham Stone, described by Professor Bonney. 



The other smaller hammers are fragments of crystalline rocks 

 and quartzite, such as might be obtained in any glacial drift or 

 gravel deposit. The flints of which the axes are made do not offer 

 any special points of interest. They may have been obtained in 

 the immediate locality. 



Sources from whence the Materials of Stonehenge were 



DERIVED. 



That the great sandstone monoliths of Stonehenge were originally 

 " grey wethers " lying upon the surface of the chalk downs, probably 

 • at no great distance from the spot where the structure stands, 



