Transactions. 35 



2iicl, With one exception, the first visited, and that ap- 

 jjarently due to the scantiness of its materials and disarrange- 

 ment of structure, the sanae can be affirmed with equal 

 certainty of the approacli alluded to, viz., a narrow passage 

 leading from the outer to the inner circle. 



3rd, This passage was found in every case to be nearly 

 due south, or, so far as my imperfect observations may be 

 depended upon, a little west of south. 



4th, The more perfect condition of the remains at Clava, 

 especially as regards two of the structures, appear to me to 

 give the key to the formation of those whose loss perfect 

 remains do not so easily indicate their original form, and 

 thus warrant the inference that the whole six were originally 

 precisely the same, viz., that each separate structure origin- 

 ally consisted of an interior chamber enclosed by a thick 

 wall, and entered through it by a narrow passage from the 

 south, and surrounding all an exterior circle of isolated 

 blocks. 



My general conclusion is that the three circles so often 

 mentioned are, 



First, the exterior one, consisting of isolated blocks, and 

 corresponding to that with which we are more familiar in 

 similar structures in our own neighbourhood. 



The second consisting of the foundation slabs which 

 originally formed the base of outer side of the wall inclosing 

 the interior chamber. 



The third consisting of the corresponding blocks on the 

 inner face of the wall — that is, constituting the boundary 

 wall of the chamber itself. 



I am further of opinion that all this is capable of simple 

 explanation, if not of easy proof. It is well known that 

 wherever the demand existed the materials of these struc- 

 tures have been devoted to utilitarian purposes, from which 

 it naturally follows that where the demand was greatest the 

 perfection of the original structures would be least. 



Thus in the three first structures visited, which lie nearer 

 to Inverness, and in a more populous district, and where the 



