The Southern Upland rocks are divided into a ' Moffat 

 Terrane ' below, with its three divisions, Glenkiln, Hartfell, and 

 Birkhill ; and a ' Gala Terrane ' above. The Moffat terrane at 

 its maximum at Girvan is about 4,000 feet thick, but it dwindles 

 to 300 or 400 feet about Moffat, and is only slightly thicker when it 

 reappears at the surface in Lakeland. The Gala terrane, 2,500 feet 

 at Girvan, at first thickens to the east and south-east, but it is 

 much attenuated in the Browgill or Pale Slates of the Lake Country. 



These points are shown in a series of magnificent sections 

 across the Southern Uplands, which demonstrate clearly the 

 Author's wonderful grasp of the complicated tectonics of the area, 

 complications of such a nature and intensity that without detailed 

 mapping the anticlines would be (and indeed had been) mistaken 

 for synclines and vice versa, and the succession read in inverted 

 order. The leading features are a great ' endocline ' (pseudo- 

 syncline or ' fan structure ') ranging from Port Patrick through 

 Carsphairn and Lead Hills, the Moorfoot and Lammermuir Hills, 

 to Dunbar ; and a great exocline (pseudo-anticline or reversed 

 ' fan structure ') from the Mull of Galloway, past Dumfries and 

 Hawick, to St. Abb's Head. Roughly parallel to these are three 

 complex anticlinal forms : (i) the Moffat-Melrose band ; (2) the 

 Leadhills-Moorfoot band ; (3) the western zones of Ballantrae and 

 Girvan. In the first band the rocks of the Moffat terrane show only 

 as narrow inliers ' at the most a score or two of yards in width ' 

 in an area consisting of dominating Gala rocks. In the second band 

 the exposures of the Moffat terrane are often more than a mile 

 in diameter and are laid bare to a depth of 2,000 feet. In the third 

 area the exposures of pre-Gala rocks are four or five miles across, 

 and denudation has cut down to the underlying Ballantrae or 

 Arenig rocks. 



These sections, not published till 1889, which, though of course 

 somewhat generalised, depict merely deductions from observed 

 facts, show clearly the thorough understanding of intensely com- 

 plicated mountain structure which Lapworth at this time possessed, 

 and indeed must have acquired by the time of the close of his 

 Upland field-work about 1881. If is most instructive to compare 

 them with what he called hypothetical sections of exoclines and 

 endoclines published in the ' Secret of the Highlands ' in 1883. 

 Nothing could better show on what a firm basis of fact, well known 

 to himself, but often unpublished, his ' hypotheses ' were always 

 based. 



Finally, he gives a summary of the knowledge so far arrived 

 at by himself as to the general geological map of South Scotland ; 

 and a careful comparison of his last paragraphs with the latest 

 results published by the Geological Survey of Scotland shows 

 how little that knowledge deserves the depreciation he expresses. 



