206 SCHOOL OF MINES AND MUSEUM CHAP, vi 



the dividing line between Upper and Lower Silurian, 

 following out what I did years ago at Builth. 



' As these maps stand, their authority is in great 

 part gone, and any one can point out their inconsist- 

 encies. I do not, however, even now dream of mend- 

 ing South Wales without special orders, since having 

 been done by others, and before my time, I have no 

 actual responsibility in the matter. When a personal 

 responsibility to you and the public weighs upon me, 

 I cannot rest till I have done my very best as long as 

 I am allowed to do it.' 



To his colleague, Salter, he was still more out- 

 spoken about the defects of the maps of South Wales : 

 'When I joined the Survey in 1841, Sir Henry and 

 Phillips did the mapping, and I took lessons and 

 looked on admiringly. I have no doubt that almost 

 all South Wales is bad, Silurian and all. There was 

 no system in the work. I suspect my work at St. 

 David's and Fishguard is pretty nearly the best of it. 

 I even separated out the Cambrian, but it was not 

 used. From Builth to Pembroke is a mull, Llandovery 

 and all. Certain I am that Sir Henry had no ground 

 for putting my Llandeilos above the Castell Crag 

 Gwyddon rock. I had nothing to do with it. Sir 

 Henry began to map it, and left it off unfinished. The 

 whole is only about ten stages better than Devon and 

 Cornwall/ 



Some of the maps and sheets of Horizontal Sec- 

 tions of North Wales having now been published, 

 Ramsay took a useful step in the spring of 1853 by 

 reading to the Geological Society a brief outline of 

 the general succession of rocks and geological structure 

 of the region, so far as these had been determined by 

 the Survey. In this paper he passed over the con- 



