[ami] sketch of the LIFE OF DR. A. C. R. SELWYN, C.M.G. 173 



the mming records. Mr. C. II. Bone was employed as artist, and C. 

 P. Gibbs as collector of fossils. 



Under cMefs like Sir Henry de la Beclie and A. C. Ramsay, Selwyn 

 made rapid strides in the science of geology, for which he had acquired 

 a taste during his stay in Switzerland. 



He remained attached to the Geological Survey of Great Britain 

 until 1852, and devoted his energies to elucidating and mapping the 

 difficult and intricate structure of the Palaeozoics of North Wales and 

 (adjacent portions of Western England. 



He is credited with no less than sixteen geological maps prepared 

 either entirely by himself or in conjunction with his chief, Sir A. C. 

 Ramsay, or the Director-General himself, or, again, with such well- 

 known men on the geological staff as Ed. Hull, W. T. Aveline, W. W. 

 Smythe, J. Phillips, S. B. Howell and his life-long particular friend 

 and colleague, J. B. Jukes. 



The geological sheets or maps of Leominster, Montgomery, Market 

 Drayton, Harlech, Bangor, Bardsey and Machynlleth are a.scribed in 

 part or in whole to the .subject of this brief sketch. 



It was during his field work in Wales that Selwyn discovered the 

 unconformity between the lowest Cambrian and the older series of 

 'schists underneath. In this classic country of the Welsh succession, 

 Selwyn and Ramsay worked together and at one of those "Councils" held 

 on the Shropshire sheets the latter wrote at the time in his field note- 

 book : — " Held n council with Selwyn on the Shropshire sheets, etc., 

 his work there and here (North Wales) is the perfection of beauty." 

 ^' One of the most striking sections of the whole series of sections pub- 

 lished by the Geological Survey," writes Sir Archibald Geikie later, 

 '' runs from the top of Snowdon parallel with the Llamberis valley to 

 the Menai straits at Llanfair, iwhence it was afterwards continued across 

 Anglesey. On the other side it was prolonged south-eastwards into 

 the country mapped by Selwyn and was carried by him into Merioneth- 

 ehire, across Cynicht, Moel Wyn and Aran Moddw}^, and was continued 

 by Aveline across Montgomeryshire." Sir Archibald adds : — " The geo- 

 logical structure is portrayed by Ramsay and Selwyn with a boldness 

 and vigour, and at the same time iwith an artistic feeling, which had 

 hardly been equalled in geological section dra^v^ng." 



In 1845 Selwyn worked out the complicated geology of the volcanic 

 district of Cadar Idris in North Wales. In the summer of 1846 he was 

 engaged in mapping out the rock formations in the Dolgelly region, 

 whilst Aveline was tracing the boundaries of the Silurian series from 

 Llanbrynmair eastward to the Church Stretton and Longmynd. Ram- 

 's? accompanied Selwyn and records : — " Glorious days and glorious 



