•28 



The next writer we find is Edward Lloyd, and one of our earliest geologists, 

 who visited this town and neighbomhood and appears to have been the first 

 who noticed the Stigmaria ficoides in the South Welsh and Monmouthshire 

 coal district, and describes it in a letter to Dr. Tancred Robinson dated Usk, 

 15th June, 1697 (published in the Philosophical Transactions 1712, vol. 27, 

 page 467). He also gives an account of a coal level, and the mode of working 

 adopted at that time — this was at Llan Elhi (Llanelly), Breconshire, and he 

 states that the roof above the coal was slate, and contained many stalks of 

 plants, which he did not save because it seemed impossible to reduce them to 

 their several species, and noticing the coal and iron mines then at work at 

 Pontypool (p. 468) he mentions leaves of " capillary plants " in the iron ore. 



Again, we have a description of the basin by Mr. Edward Martin, read 

 before the Royal Society 22nd May, 1806. 



Next Dr. Buckland, and the Rev. W. D. Coneybeare (afterwards Dean of 

 Llandaff) in 1822, in a paper entitled Observations on the South Western 

 district of England, " Geological Transactions," vol. 1 part 2, second series, 

 pomted out the comiection of the coal districts of Somerset, Gloucestershire, 

 Monmouthshire, and Glamorganshire, followed by a paper by Mr. Francis 

 Forster, Observations on the South Welsh Coal Basin, read June 15th, IS.'iO, 

 before the Natural History Society of Northumberland and Durham. 



In 1833 Mr. Robert Bakewell, in his work on Geology, describes the field. 



In 1846, vol. 1 of the "Memoirs of the Geological Survey of Great 

 Britain " was published containing a lengthy and well-written paper by Sir 

 Henry T. De la Beche on the formation of the Rocks of South Wales and 

 South -Western England. 



In 1860 a carefully-prepared paper on the field was published by the Hon. 

 Member for Glamorganshire, Mr. H. Hussey Vivian. 



■ Mr. Hull, in 1861, gives a chapter on the Great Coalfield of South Wales 

 in his work " The Coal Fielfls of Great Britain," and numerous other writers 

 have drawn attention to the district, so that but little more remains to be said 

 upon the subject. 



The extent of the South Wales Coal Field (that is of the coal-producing 

 strata) is from Blaenafon and Pontypool on the Eastern outcrop to St. Bride's 

 Bay, Pembrokeshire, on the west, a length of about ninety miles ; the width 

 varying from the north to the south outcrop, say in Monmouthshire and 

 Glamorganshire up to the river Loughor (the county boundary with Caermar- 

 thenshire) about sixteen miles (in this is included the small area lying in 

 Breconshire) ; from Loughor river to Kidwelly and Caermarthen Bay about 

 ten miles ; under the Bay to Saundersfoot, about 5 miles ; and from Saunders- 

 foot through Pembrokeshire to St. Bride's Bay, an average width of four 

 miles. 



The superficial area is difi'erently estimated by the variouB writers, the 

 lowest being Mr. Hull, who gives it at 806 square miles or 579,840 acres; another, 

 935 square miles or 598,400 acres ; another, 960 square miles or 614,400 acres ; 



