NA TURE 



[January 26, 1905 



Reg;arding both circles and alifjnments in the light 

 of the orientation theory, we may consider simple 

 circles with a central stone as a collection of sight- 

 lines from the central stone to one or more of the 

 outer ones, or the interval between them, indicating 

 the place of the rise or setting of either the sun or 

 a star on some particular day of the year, which day 

 will be a new year's day. 



Fig 



-Plan of Stonehenge, standin 



haded. A, Stc 

 in 1900 ; BH, htones which fell in 1797. 

 (Reproduced f>-om '• Jlfan.") 



Alignments, on the other hand, will play the same 

 part as the sight-lines in the circles. 



Sometimes the sight-line may be indicated by a 

 menhir outside, and even at a considerable distance 

 from, the circle. 



The dolmens have. I am convinced, been in manv 



In order to bring some measurements to test the 

 orientation theory in Britain, I found that Stonehenge 

 is the ancient monument in this country which lends 

 itself to accurate theodolite work better than any 

 other. Avebury and Stanton Drew are known to a 

 great many archaeologists ; there are also other very 

 wonderful stone circles near Keswick and in other 

 parts of England;' but unfortunately it is very much 

 more difficult to get astronomical data from these 

 ancient monuments than it is in the case of Stone- 

 henge, one reason being that Stonehenge itself lies 

 high, and the horizon round it in all directions is 

 pretty nearly the same height, so that the important 

 question of the heights of the hills along the sight- 

 line — a matter which is very important from an astro- 

 ]iomical point of view, although it has been neglected, 

 so far as I can make out, by manv who have made 

 observations on these ancient monuments — is quite a 

 simple one at Stonehenge. Hence it was much easier 

 to determine a date there than by working at any 

 of the other ancient remains to which I have referred. 



In orientation generally, such orientation as has 

 been dealt with by Mr. Penrose and myself in Egypt 

 and in Greece, the question frequently was a change 

 in direction in the axis of a temple, or the lay- 

 ing down of the axis of a temple, by means of 

 observations of stars. Unfortunately for us as 

 archaeologists, not as astronomers, the changes of 

 position of these stars, owing to certain causes, chiefly 

 the precessional movement, are very considerable; so 

 that if a temple pointed to a star in one year, in 

 two or three hundred years it would no longer point 

 to the same star, but to another one. 



Acting on a very old tradition, the people from 

 Salisbury and other surrounding places go to observe 

 the sunrise on the longest day of the year at Stone- 

 henge. We therefore are perfectly justified in assum- 

 ing that it was a solar temple used for observation 

 in the height of midsummer. But at dawn in mid- 



w of Stonehenge from the west. A, Stone which fell in 1900 ; BB, Stone 

 {.Reproduced ^roni an account of the /alien stones by Mr. Lewis in ' 



crises not graves originally, but darkened observing 

 places whence to observe along a sight-line ; this 

 would be best done by means of an allee couverte, 

 the predecessor of the darkened naos at Stonehenge, 

 shielded by its covered trilithons. 



NO. 1839, vol .71] 



siMiinier in these hititude> the sky is so bright that 

 it is not easy to see stars even if we get up in the 

 morning to look for them ; stars, therefore, were not 

 in question, so that some other principle had to be 

 adopted, .-ind that was to point the temple directly to 



