50 Proceedings of the Royal Physical Society. 



From the pressure exerted on their surfaces, they cannot rest 

 unless either lying horizontally or dipping in the direction 

 where the current flowed, or towards the source. In this 

 case the current which assorted the boulders in the sand, had 

 an easterly direction. It is difficult to find, in the boulder 

 clay itself, satisfactory examples sufficiently numerous, among 

 the generally rounded blocks, from which to draw any infer- 

 ence." 



The destruction caused to property round Canonmills, in 

 the autumn of 1877, by the floods of the Water of Leith, was 

 evidence of the carrying and carving power of that rather 

 insignificant stream in an ordinary season. Geologists had 

 previously noted sections of its bed showing rapid action. 

 Thus in digging for the foundations on the north side of 

 Charlotte Place, to the west of St George's Church, Fleming 

 records the finding of a bed of from 2 to 3 feet of angular 

 fragments or shivers of bituminous shale, resting on the fixed 

 strata of the same material. " The boulder clay rested on the 

 shivers, and seemed to have had a motion from west to east." 

 In one place it had caused pipes of the shivers, below and 

 above the regular bed. In some places again a sand-bed 

 interposes betwixt the two layers. Mr John Henderson has 

 since described a somewhat similar section in the upper 

 course of the stream above Colinton. But at the site of the 

 gasometers, beside the once celebrated Tanfield Hall, on the 

 road to Newhaven, several of such sections have been noted. 



Both of the companies supplying Edinburgh have depots 

 at this locality. 



The following quotation, from Fleming's "Lithology of 

 Edinburgh," p. 52, refers to the first and westermost gasometer 

 erected by the Edinburgh and Leith Gas Company, on the 

 Brandon Street side of the river : " When the foundation for 

 the gasometer on the south side of the Water of Leith, at 

 Tanfield, was being dug, a similar display of the junction of 

 the shivers with the boulder clay presented itself. In this 

 case, and the former, the shivers sometimes reached the length 

 of 3 or 4 inches. Here they consisted of a light-coloured 

 somewhat indurated slate-clay, occasionally arenaceous. This 

 mass of fragments, forming a bed from 2 to 3 feet in thick- 



