452 ANNUAL REPORT S^QTHSONIAN INSTITUTION, 1940 



Avebury, the older of the two, has been partly destroyed, but when 

 perfect was one of the largest. 



Stonehenge is the most finished example of a megalithic circle in 

 England. 



THE LITHOLOGY OF STONEHENGE 



Weatherworn and overgrown by lichen, it is not possible at the pres- 

 ent day to see clearly the nature of the stones which go to make up 

 Stonehenge. Investigation reveals the fact that the stones vary very 

 much in material, and that, further, just as the stones are placed in 

 sj^stematic order, so too has the same care been exercised in the selec- 

 tion of the material from which each circle or horseshoe has been 

 built. 



Moreover, just as the stones can be divided into groups of uprights 

 with lintels, or "Trilithons" and "simple uprights," so too has it been 

 found that while all the Trilithons are composed of "local" stone 

 known generally as "Sarsen," all the simple uprights are of Prescelly 

 stone, or "bluestone," as it is generally called. This term must be 

 understood in a very comprehensive sense, since the simple uprights 

 show considerable variation in structure, but one and all are foreign 

 to the County of Wiltshire, whereas the larger Sarsen blocks, which 

 were formerly scattered all over the Wiltshire Downs, still exist in 

 some parts in considerable numbers. 



THE SARSEN STONES 



All the large stones comprising the Trilithons are "Sarsens" which 

 have come from Wiltshire. They are found in the form of boulders, 

 and are picturesquely called "grey wethers." The name is an apt 

 one, since in North Wiltshire, where they are more plentiful, they 

 certainly suggest a flock of titanic sheep reclining at ease on the 

 pasturage of the Downs. The hand of man has been heavy upon the 

 Sarsens, in a country which has little stone and that only in the 

 form of flint. Sarsens have been even quite recently used for pav- 

 ing stones and kerbs in Wiltshire towns. They are also to be foimd 

 in the walls of churches, while the village of Avebury itself affords 

 an example of how the Great Circle there has been depleted for 

 building purposes. No doubt the stones were far more plentiful in 

 prehistoric times, but even admitting this, it seems hardly likely that 

 the large tabular blocks used at Stonehenge could have been found 

 in the immediate neighborhood. On closer examination the "Sarsen" 

 shows itself to be a sandstone, formed by the natural cementing to- 

 gether of the sand and gravel which overlay the chalk in Tertiary 

 times. The stone is of very uneven texture, some specimens being 

 very compact and hard, while others are friable and easily disinte- 

 grated. One thing is very certain, however; the building of both 



