72 Stonehenge and its Barrows. 



gravels, were deposited upon it. These constitute what are now 

 called the tertiary strata. When they were subsequently raised 

 above the bed of the ocean, they were exposed to the powerful de- 

 nuding action of seas, glaciers, and rivers, by which the main portion 

 of them, in the western district (Wiltshire included), was carried 

 away ; a few cappings on some of the hills only remaining through 

 the greater part of our county. Such cappings are not uncommon 

 on some of the high hills on the borders of Salisbury Plain, es- 

 pecially to the northward and eastward of Amesbury, and between 

 that town, Bedwyn, and Kingsclere ; whilst hills, where no masses 

 of tertaries remain, shew by the presence of numerous tertiary flint 

 pebbles on their summit, the wreck of strata once spread over this 

 area. Among the lower iertiaries (the Eocene of Sir Charles Lyell), 

 are certain sands and mottled clays, named by Mr. Prestwich the 

 Woolwich and Reading beds, from their being largely developed at 

 these places, and from these he proves the sarsens to have been 

 derived; although they are seldom found in situ, owing to the 

 destruction of the stratum to whieh they belonged. They are large 

 masses of sand concreted together by a silicious cement, and when the 

 looser portions of the stratum were washed away, the blocks of sandy 

 rock were left scattered over the surface of the ground. 



"At Standen, near Hungerford, large masses of sarsen are found, 

 consisting almost entirely of flints, formed into conglomerate with 

 the sand. Flints are also common in some of the large stones 

 forming the ancient temple of Avebury. 



" At the cliffs of St. Marguerite, near Dieppe, is a bed of fine 

 white sand, reposing unevenly upon the chalk, and extending for 

 one or two miles in length. It contains blocks of concretionaiy 

 silicious sandstone, frequently measuring many feet in length. A 

 good example of sarsen stone in situ. 



" The abundance of these remains, especially in some of the valleys 

 of North Wilts, is veiy remarkable. Few persons who have not 

 seen them can form an adequate idea of the extraordinary scene 

 presented to the eye of the spectator, who standing on the brow of 

 one of the hills near Clatford, sees stretching for miles before him, 

 countless numbers of these enormous stones, occupying the middle 



