232 Reviews— IT. M. Cadell— Geology of Sutherland. 



and memoirs concerning this matter, with reference to Sutherland, 

 is given by Mr. Cadell at pages 15 and 16. 



The geology and scenery of North-western Scotland are then 

 described in some detail, with the latest information, and In 

 commonplace language, as far as the subject will allow, the author 

 attempting, more or less successfully, to make it light literature. 

 The foundation-rock or basement is the "old gneiss," composed of 

 crumpled sheets of mineral matter, penetrated throughout by veins 

 of other kinds of rock, relatively harder or softer, that have either 

 filled its cracks or made their way into it. 



The history of the " Gneiss " seems to us to be romantic. As 

 with mythic heroes, its origin or parentage is doubtful or unknown. 

 Its record begins with the evidence of the troubles it underwent, 

 overcoming difficulties by giving way to them, and becoming 

 self-consistent and harder (fig. opposite p. 36). So it presented 

 a tough and jagged surface, which the envious ocean smothered with 

 sand and pebbles (fig. 1, p. 46). Then, Titan-like, it forced its way 

 upwards with the superincumbent burden (fig. 2, p. 47) ; to be cut 

 clown to a level by long wear and tear of the water-world, and again 

 entombed by inimical agencies (fig. 3). At last, within the 

 " to-day " of some millions of our years, it has once more regained 

 its land-level; and now exhibits (in Scrishven, Quinag, Canisp, 

 Suilven, and Coulmore ; and along the region from Durness and 

 Eriboll on the north, to Ullapool on the south) evidences of the victory 

 of its persistent upward movement, bearing a load of trophies from 

 its primeval entombments. Fig. 4, p. 48, shows these results of 

 " latest upheaval, tilting, and denudation." The same kind of 

 natural forces which originally folded and crumpled the gneiss, 

 still squeezing both the underlying and the overlying rocks and 

 strata, elevated this region, as also other parts of the earth's crust, 

 by causing undulations and foldings to rise above the general level ; 

 and gave them side-movements and lateral thrusts, which broke 

 them into sloping segments and pushed them one over another for 

 a distance of even ten miles. The pressure of the displaced rock- 

 masses one on another, along the planes of the thrusts, has ground 

 down their surfaces into material differing from the original — now 

 fragmentary and granular, and yet not due to any deposition in 

 water. 



These violent changes in position and substance of the rocks con- 

 fused the early observers, and were very gradually realized, and only 

 of late elucidated, by many enthusiastic geologists giving time 

 and labour, for pleasure or duty, among the wild highlands of 

 Sutherland. 



An interesting chapter (pp. 68-76) details the circumstances 

 under which the author carried on some experiments, with 

 alternating laj'ers of stucco-powder or foundiy-loam and of damp 

 sand, squeezed horizontally in a suitable press-box. A succession of 

 obliquely faulted segments of one band, riding one over another at. 

 the point oVappui in the box, agreeably represented the structure of 

 Aikle or Crea£ Dionard. Another series of such thrusts on a small 



