r/\) ISI5 (5or«gU Ittiueraitg liibrarg BOUGHT WrTH THE INCOME OF THE SAGE ENDOWMENT FUND THE GIFT OF HENRY W. SAGE 1891 fNGINEERING LIBRARY »m3ws when this voltune was taken, t o reuew xnis book copy the call No. and give to the librarian. HOME USE RULES All Books Bubject to recall All borrowers must regis- ter in the library to borrow books for home use. All books must be re- turned at end of college year for inspection and , , repairs. Limited books must be returned within the four week limit and not renewed. Students must return all books before leaving town. Officers should arrange for the return of books wanted during their absence from town. Volumes of periodicals and of pamphlets are held in the library as much as possible. For special pur- poses they are given out for a limited time. ■ ■ Borrowers should not use their library privileges for ' the benefit of other persons. , Books of special value and gift books, when the , giver wishes it, are not allowed to circulate. Readers are asked to re- port all cases of books marked or mutilated. Do not deface books by marks and writing. Cornell University Library TN 808.G7S89 1915 The coals of South Wales. With specj^^^^^^^ 3 1924 004 555 177 Cornell University Library The original of tiiis book is in tine Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924004555177 MEMOIRS OF THE GEOLOGICAL SURVEY ENGLAND AND WALES. THE COALS OF SOUTH WALES. WITH SPECIAL REFEEENOE TO THE ORIGIN AND DISTRIBUTION OF ANTHRACITE. By AUBEEY STEAHAN, M.A., ScD., LL.D., F.B.S., AND W. POLLAED, M.A., D.Sc, F.I.C. Assisted by E. G. RADLEY. Second Edition. PUBLISHED BT OaU£R OF THE LOHDB Ci)UMISBION£IlS OF HIS MAJESTY'S TREABURT. LONDON : PRINTED FOR HIS MAJESTY'S STATIONERY OFFICE By JAS. TRUSCOTT and SON, Ltd., Cannon Street, E.G. And to be purchased from E. STANFORD, I/td., 12, 13 and 14, Long Aoeb, London ; W. & A. K. JOHNSTON, Ltd., 2, St. Andeew SgnABE, Edinbubgh jHODGES, FIGGIS & Co., Ltd., Grafton Street, Dubmn ; ■ from any Agent for the sale of Ordnance Survey Mapa; or through any Bookseller from T. FISHER UNWIN, 1, Adelphi Terrace, London, W.C. who is the Sole Wholesale Agent to the Trade outside the County of London. 1915. Price Two Shillings. GEOLOGICAL SURVEY and MUSEUM. (Office: 28, Jeemtn Stbeet, London, S.W.)- PUBLICATIONS RELATING TO THE SIX-INCH SURVEY OF SOUTH WALES. MAPS. GENERAL MAP ON THE SCALE OP i INCH=1 MILE (1 to 253440). South Wales, with parts of Central Wales and North Devon and Somerset, is included in Sheets 13 (with part of 17), 14, and 18 (with part of 17), price 2s. Gd. each. ONE-INCH MAPS, NEW SERIES, ON THE SCALE OF 1 INCH=1 MILE (1 to 63360). Each map is published in a Drift and Solid Edition, price Is. 6d. each, with the exception of Sheet 228, which is in course of preparation. Sheet 249 (Newport) 1895, with Explanatory Memoir, 2nd Edition, price Is. 6d. (1909). Sheet 232 (Abergavenny) 1896, with Explanatory Memoir, price 2». (1900). Out of print. Sheet 263 (Cardiff) 1897, with Explanatory Memoir, 2nd Edition, price 2s. (1912). Sheet 248 (Pontypridd and Maesteg) 1898, 2nd Edition of Memoir in .preparation'. Sheet 231 (Merthyr Tydfil) 1900, with Explanatory Memoir, price 1». Gd. (1904). Sheet 261-2 (Bridgend) 1901, with Explanatory Memoir, price Is. Gd. (1904). Sheet 230 (Ammanford) 1907, with Explanatory Memoir, price 2s. Gd. (1907). Sheet 247 (Swansea) 1907, with Explanatory Memoir, price 2s. Gd. (1907). Sheet 246 (West Gower) 1906, with Explanatory Memoir, price Os. 8d. (1907). Sheet 229 (Carmarthen) 1909, with Explanatory Memoir, price 2s. (1909). Sheet 228 (Haverfordwest). Explanatory Memoir, price 3s. 6d. (1914). MEMOIRS OF THE GEOLOGICAL SURVEY ENGLAND AND WALES. THE COALS OF SOUTH WALES. WITH SPECIAL EEFERENCE TO THE ORIGIN AND DISTRIBUTION OF ANTHRACITE. By AUBREY STRAHAN, M.A., Sc.D., LL.U., T.R.S., AND W. POLLARD, M.A., D.Sc, F.I.C. Assisted by E. G. RADLEY. Second Edition. PUBLISHKD ItY ORDBK OF THE L0ED8 COMMISBIONEHS OF UlS MAJESTY S TllKASURY. LONDON : PRINTED FOR HIS MAJESTY'S STATIONERY OFFICE By JAS. TRUSCOTT and SON, Lip., Cannon Steebt, E.C. And to be purchased from E. STANFORD, Ltd., 12, 13 and 14, Long Aoeb, London ; W. & A. K. JOHNSTON, Ltd., 2, St. Andrew Square, Edinburgh ; HODGES, FIGGIS & Co., Ltd., Geaiton Street, Dubun ; from any Agent for the sale of Ordnance Survey Maps ; or through any Bookseller from T. FISHER UNWIN, 1, Adblphi Terrace, London, W.C. who is the Sole Wholesale Agent to the Trade outside the County of London. 1915. Price Two Shillivgs. TM "in A4io^'=}ss in . PREFACE TO THE FIEST EDITION. Preparations for this Memoir on tli« Coals of South Wales were^ commenced in 1901, when Sir Archibald Geikie was Director-General of the Geological Survey, and the collection of material has proceeded since that date, as circumstances allowed. Though obviously incomplete, in the sense that analyses might be multiplied indefinitely, the work had so far progressed in 1907 as to lead to a more or less definite opinion as to the relative distribution of anthracitic and bituminous coals, and as to the origin of the difference between them. The time appeared, therefore, to have arrived for publication of the results, though admittedly a larger number of analyses would add precision to the generalisations, and illustrate more fully certain seams and certain parts of the coalfield. Necessarily there was much doubt at its inception what form the investigation should take. That each seam should be examined separately, and its modifications traced step by step from the bituminous into the anthracitic region, was clear. It was desirable also that all analyses should be made on a uniform system. For various reasons, explained in the following pages, it was impossible to follow fully so ideal a scheme. Samples of •coal were not always procurable from the desired seam or locality, while a large number of analyses, the accuracy of which there was no reason to doubt, would have been inadmissible. Eventually it was decided that while special attention was being devoted to certain seams, opportunities ought not to be lost of getting specimens of others which happened to be accessible. Difiiculty arose also from the natural reluctance of the colliery proprietors to consent to the publication of coal-anah'ses over which they had had no control. This was overcome by the assistance kindly rendered by the South Wales Institute of Engineers. Not only was an arrangement made with the pro- prietors under which specimens could be collected and analyses published, but through Mr. Jones Price, Secretary to the Institute, we were kept informed where specimens could be procured. This volume, which is the outcome of the investigation, has (3762.) Wt. 48117— 83. 1,000. 7/15. J. T.&S. G. 14 a2 been written bj- Dr. Stralian and Dr. Pollard. The latter, with the assistance of Mr. E. G. Radley, has carried out all the chemical work, excej)t some analyses which were made for the Geological Survey by Mr. C. A. Seyler. To Dr. Pollard also are due the chapters dealing with the methods of analysis, possible causes of error in analysis, and the classification of coals. The ' relation of carbon, to hydrbgen having proved to be the most reliable factor for expressing the character of the coal as regards anthracitism, the series of maps (forming Plates 3-7) were prepared to illustrate the distribution of anthracite on this basis. So far as we are aware, this is the first attempt to define the distribution of anthracite on purely experimental data. Our thanks are due to Mr. Seyler for much assistance. He has not only furnished us with a large number of analyses, made independently of this investigation, but has given advice of great value in deciding on the method of analysis. We have also had the benefit of his comments on this volume during its passage through the press. J. J. H. TEALL, Director. Geological Suirey Office, .28, Jennijn Street, London, 17th February, 1908. P E E F A C E TO THE SECOND EDITION. In the preparation of a second edition of this Memoir, Dr. Pollard, who retired from the Geological Survey in 1913, has been so kind as to give his services. A large number of new analyses has been added, partly of samples collected by the Survey during a recent revision of some of the maps, and partly through the kindness of Mr. C. A. Seyler. The actual number of additional analyses is 118, and of these 15 were made by Mr. Eadley under the supervision of Dr. Pollard before his retirement, 46 were of samples collected by the Survey but analysed by the Government Laboratory and 57 were by Mr. Seyler. The methods of analysis employed were in all cases such as to give strictly comparable results. For facilities in collecting the new samples we are indebted to a large number of Colliery Proprietors and OflEicials, who in all cases cordially gave their assistance to our collectors. The same conditions as regards methods of collecting and the publication of the names of the collieries were observed as in 1908. A consideration of the new data thus made available has rendered possible slight readjustments of the lines of isoan- thracitisation shown on the charts, all tending towards greater precision in those spots where the evidence was defec- tive. The result has been to confirm the general conclusions put forward in the first edition of the Memoir as io the dis- tribution of the different varieties of coal, and to strengthen the arguments which were advanced that the differences are in the main original and not due to subsequent alteration. A. STEAHAN, Director. Geological Survey Office, 28, Jermyn Street, London, S.W., 30th April, 1915. ' VI CONTENTS. Peef ACE by the Director 2nd Ed. .... Chapter I. — Historical and Introductory Chapter II. — Sequence of the Coal-seams Chapter III.— Analytical Methods and Table of Analyses Chapter IV. — Accuracy of Coal Analyses Chapter V. — Comparison of different bands of the same Seam, and Comparison of different Samples from the same Seam in the same Locality Chapter VI. — ^Comparison of different Seams in the same Locality Chapter VII. — Classification of Coals Chapter VIII. — Explanation of the Iso-anthracitic Charts (Plates 3 to 8) Chapter IX. — Origin of Anthracite Index page iii v 1 4 6 33 46 51 58 65 73 87 ILLUSTEATIONS. {At end of Volume.) Plate I.- Plate 2.- Plate 3.- Plate 4.- Plate S.- Plate 6.- Plate 7.- Plate S.- Plate 9.- Plate 10. -Map of the South Wales Coalfield, showing Railways and Positions of Analyses. -Comparative Sections of the Coal Measures of South Wales, showing the Position and Correlation of the Coal-seams referred to. -Map of the South Wales Coalfield, showing Iso-anthracitic Lines in the Seams below the Ras-las Vein. -Map of the South Wales Coalfield, showing Iso-anthracitic Lines in the Bas-las, Nine Feet or StanUyd Vein. -Map of the South Wales Coalfield, showing Iso-anthracitic Lines in the Veins between the Ras-las and the No. 3 Rhondda Veins. -Map of the South Wales Coalfield, showing Iso-anthraoitie Lines in the No. 2 Rhondda and Hughes Veins. -Map of the South Wales Coalfield, showing Iso-anthracitic Lines in the Mynyddislwyn, Swansea Pour Feet, and Swansea Six Feet (Graigola) Veins. -To show the Rate of the Change in Anthracitic Character from South to North in the Swansea Five Feet Vein. ^ -To show the Percentage of Ash increasing with the Bituminous Constituent. —Map of the South Wales Coalfield, showing Position of Measure- ments of Strata. THE COALS OF SOUTH WALES. WITH SPECIAL EEPEEENCE TO THE ORIGIlSr AND DISTEIBUTION OF ANTHRACITE. CHAPTER I. Historical and Introductory. By A. Strai-ian. The existence 'of anthracite in tlie South Wales coalfield was well known to the earliest miners of whom records exist, and the part of the coalfield to which anthracite was limited was' roughly defined, so far as regards the small depths they were able to attain. Leland, for example, mentions that the coals of the Gwendraeth-fawr are anthracite (stone coals), while those of Llanelly are bituminous (ring coals).* "The development of the coalfield, however, during the last 100 years has added much to the superficial observations first made, and has shown that the gradation into anthracite proceeds in accordance with certain general laws, the investigation of which seems likely to lead to results of both scientific and economic value. The changes undergone by the coal present certain stages, which, though recognised commercially, are not capable of exact definition : from house-coal, or the most bituminous, the change is gradual into steam-coal, and from steam-coal into anthracite. The facts reported with respect to the changes are as follows : — 1st. — The anthracitic regions lie in the north-western corner of the Carmarthenshire, Brecknock, and Glamorganshire field, and in Pembrokeshire. In the former, which we may call the main coalfield, the seams become gradually less bituminous in approaching the anthracitic region. The change takes place from east to west along the north crop in the eastern end of the coalfield, from south-east to north-west nearer to Cardiff, and from south to north near Swansea and in the western part of the main coalfield. In other words, lines of equal anthracitisa- tion circle round an area which extends from Kidwelly to Glyn Neath. In Pembrokeshire all the coal is anthracitic. 2nd. — The seams all show the change on approaching the anthracitic region, but the higher seams show it later than- the * " At LLanelthle, a Village of KidweUi Lordship, a. vi. miles from Kidwelli, the Inhabitans digge Coles, eUes scant in Kidwelly Land. Ther be ii. Maner of thes Coles. Ring Coles for Smith be blowid and waterid. Stones Cole be sumtime waterid, but never blowen. For blowing extinguishit them. So that Vendioith Vaur Coles be Stone Coles ; LLanetMe Coles Ring Colis." . (" The Itinerary of John Leland the Antiquary," vol. 5. PubHahed from the original Ms. in the Bodleian Library, by Thomas Hearne, M.A., Oxford 1744.) -i THE COAL OF SOUTH WALES. lower. Thus No. 2 Rliondda Coal keeps its character as a house- coal to within about 25 miles of the anthracitic centre, and then becomes a steam-coal. The house-coals, about 400 yards beldw, become steam-coals about 30 or 40 miles from the anthra- citic centre, and then occur as anthracite for a distance of about 25 miles. It follows that in any one deep shaft the shallower seams, should be more bituminous than the deeper, and this as a fact has been proved to be generally the case. 3rdly. — The loss of bituminous matter takes place at a more rapid rate in a south-to-north direction than in an east-to-west direction. This fact, taken in connection with the general form of the anthracitic region, so far as it has survived denudation, indicates that the original area of anthracitic coal was elongated in an east-and-west direction. It is obvious, moreover, that that area did not even approximately coincide with the existing coalfield, but lay, for the most part, outside it to the north and north-west. There have been many speculations on the reasons for the diminution in bituminous matter. But while it was easy to find serious objection to every theory that had been advanced, the facts were not sufiiciently definite to enable any fresh hypothesis to be put forward with confidence. A large number of analyses had been made, partly in connection with an ofiicial report written in 1848 by De la Beche and Playfair on " Coals suited to the Steam Navy," and partly for Dr. Percy for the purposes of his work on " Met^illurgy." Of later years many analyses had been carried out by Mr. C. A. Seyler, to whom is due the credit of having taken the first steps towards a systematic classi- fication of South Wales coals. Many others also had been furnished to coUiery-propiietors by various analysts, but of these several were useless for the present purpose, some because the name of the seam was not given, others inasmuch as they were only proximate. Finally, a large series of analyses, including many of South Wales, had been collected in a useful publication by the Colliery Guardian Company. It was clearly desirable, however, for the special purpose in view, that not only should all available analyses be collected and compared, but that all should be referred to their proper horizons in the Coal Measures, and that the series should be supplemented when necessary for the investigation of the change in character of any j^arficular seam. Arrangements were com- menced for the collecting and analysing of such further samples as might be required in January, 1901, by the sanction of Sir A. Geikie, at that time Director-General of the Geological Survey. In view of the difiiculty of knowing where a seam of which a specimen was required was at the moment being worked, and of obtaining the consent of the colliery-proprietors to fresh analyses being published, the advice of the South Wales Institute of Engineers was sought, with the result that on the 14th of January the Council appointed a Committee of the following gentlemen as being representative of every part of the coal- field : — The President (Mr. Thomas Evens), Messrs. Archibald Hood, H. K. Jordan, H. W. Martin, W, D. Wight, John INTRODTJCTORT. O Eoberts, Hugh Bramwell, Fox Tallis, W. Stewart, W. Forster Brown, James Barrow. Eventually the task of ascertaining in what localities specimens could be obtained, and of communi- cating with the colliery-proprietors, fell to the Secretary of the Institute, Mr. T. Jones Price, whose cordial co-operation in the work proved to be invaluable. It was arranged with the colliery-proprietors that the analyses might be published, but that the localities from which the samples were obtained should be indicated by numbers only on a general map of the coalfield, and that the names of the collieries should not be mentioned. These conditions have been complied with. In selecting specimens with the special object in view of illus- trating the progress of the change in the composition of the coal, it was obviously advisable to deal with each seam separately. It was useless, for example, to compare n seam high up in the Coal Measures in one locality with a seam near the base of the Coal Measures elsewhere. Specimens from the same seam, on the other hand, would be comparable in different localities, though they might be obtained from different depths below the surface. It seemed to be advisable, therefore, to select for the investigation a few of the more important seams, and especially those which could be recognised over wide areas. Subsequently difficulties arose in consequence of the selected seams not being accessible in regions from which specimens were desired, and from other causes, while at the same time, from a rigid adherence to this scheme, opportunities of getting specimens from other seams would have been lost. The bulk of the pub- lished analyses, moreover, could not have been utilised. While, therefore, the desirability of obtaining a series of analyses illus- trative of the changes in any one seam was not lost sight of, analyses of other coals of local importance have been included in the lists. The collecting was commenced in 1901. It was arranged that the collector should be conducted, at every colliery he visited, to a working face where a typical development of the seam was exhibited, and that coal should be cut by an official of the col- liery from all parts of the face, except those partings which are separated out by the miners. The coal thus cut was sampled by the collector in the usual manner, and the sample was enclosed in a box with a printed form filled in by the colliery-manager, on which were given the name and section of the seam, depth from surface, and other particulars. In 1908, when revision was made of Sheet 249; in preparation of a new edition of the Memoir on the Geology of the Country around Newport, the opportunity was taken to collect further samples'(Nos. 204r-218) from the collieries situated within that sheet. Similarly in 1913, when a new edition of the Memoir on the Geology of the Country around Pontypridd and Maesteg was in preparation, a collection of the samples Nos. 219-264 was made from that neighbourhood. The same arrangements as regards the collecting and the indication of localities were observed as in 1901. CHAPTER II. Sequence or the Seams. By A. Steahan. In view of the importance of considering tlie analyses of each seam separately, it becomes necessary to correlate, as far as possible, the seams of one part of the coalfield with those of another. In Plate 2 a series of vertical sections, ranging from the east to the west end of the coalfield, is arranged with the principal seam of the most productive belt of the measures as a datum-line. Above and below the datum-line the various seams referred to in the table of analyses are inserted in their proper respective positions, but the table does not profess to give a complete list of all the seams known to occur in South Wales. The recognition of the seam selected as a datum-line may be regarded as fairly certain from Pontypool westwards so far as the Neath Valley along the North Crop. Its identification as the Nine Foot near Aberavan in the South Crop, and as the Stanllyd or Big Vein in the more western sections, is open to doubt. But though individual seams are difficult to identify, the productive belt as a whole is easily recognised. The identi- fication of the principal seam in this belt as one and the same / seam, while admittedly unproved, is put forward as the most probable, and as being certainly not far from the truth. The analyses of the seam thus selected are illustrated by the map forming Plate 4. No individual correlation of the seams below the datum-line has been attempted. Locally some of them are valuable, but no one of them can be traced continuously over more than a small part of the coalfield. The analyses of these coals are grouped together in the map forming Plate 3. The group of veins shown close above the datum-line in the five right-hand columns of Plate 2 yields the bulk of the best smokeless steam-coal of Glamorganshire. Though the veins are not everywhere individually recognisable the group persists along the northern and central parts of the coalfield from Pontypool to the Neath Yallej. West of that valley and in the South Crop the seams in the corresponding position change greatly in number and thickness. The analyses of the veins belonging to this horizon are presented in the map forming Plate 5. The identification of the seam known as the Tillery Vein in Monmouthshire, with that known as the No. 2 Rhondda or Brithdir Seam in Glamorganshire, and by other names in various parts of the coalfield, has been discussed in every suc- ceeding Part of the Memoir on the South Wales Coalfield, and needs no further comment here. The analyses are shown on Plate 6. • The correlation of the Mynyddislwyn Vein with the Llantwit No. 3, the Wernffraith or Swansea Four Feet and the Box Big of Llanelly, is less capable of proof. Its correlation with the SEQUENCE OF THE SEAMS. Llantwit No. 3 has beeu adopted in accordance with arguments brought forward by Mr. H. K. Jordan* in preference to the correlation with Llantwit No. 1 which was originally selected. The reasons for identifying Llantwit No. 3 with the WernfEraith or Swansea Four Feet vein are explained in "The Country around Swansea " (Mem. Geol. Survey), 1907, pp. 33-35, but by some authorities the Graigola Vein of Swansea is regarded aa the equivalent of the Mynyddislwyn. That the Wernflraith, Swansea Four Feet and Box Big are one and the same vein is generally admitted. The analyses of the Mynyddislwyn Vein and its supposed equivalents are inserted in Plate 7, together with those of some of, the veins which occur between it and the No. 2 Ehondda seam. Two facts are illustrated by the series of sections forming Plate 2. Firstly, that the measures expand rapidly from east to west, the thickness intervening between the Mynyddislwyn and the lowest seam at Pontypool being little more than a quarter of the thickness between the Box Big and the lowest seam near Llanelly. Secondly, that an expansion takes place also from north to south, ,the thickness near Aberavan in the South Crop being considerably greater than that in the North Crop on the same line of longitude. One exception to this rule is to be observed : locally, near Pontypool, there is a southerly and easterly attenuation, the smallest thickness known in any part of the coalfield being found near Cwm Bran. The greatest thickness on the other hand is reached in the south-west part of the coalfield, where no less than 5,700 feet intervene between the Box Big and the datum-line. Whether there is any con- nection between the varying thickness of the measures and the anthracitic character of the coal will be discussed in Chapter IX. Proc. S. Wales Inst. Erig., vol. xxiii. (1903), pp. 190-204, 323-337. CHAPTEE III. Analytical Methods and Table of Analyses. By W. Pollard. The methods of analysis employed for those analyses made in the Geological Survey Laboratory are given rather fully, asit is well known that variation in method in coal-analysis (especially in the determination of volatile matter) may produce variation in results. For the most part the methods are practically the same as those recommended hj the Commission on Coal-analysis of the American Chemical Society.* Sampling. — The samples as received at the laboratory are packed in large biscuit-tins enclosed in wooden boxe.s. The weight of the sample is 20 to 30 lbs. Usually it contains no large pieces, but all larger than a small orange are broken and the whole sample passed through a 1-in. sieve. After thorough mixing it is quartered in the usual way, the rejected half being at once replaced in the tin, whilst the other half is passed through a small Marsden-Blake crusher, and reduced by quartering to about 1 lb. This is then ground in a coifee-mill, set fine, halved and transferred to two stoppered bottles, the one for analysis, the other being tied down and sealed, in case it be required for future reference. The sample obtained by grinding in the coffee-mill is used for moisture and volatile matter esti- mations. For all other estimations a portion of this is further ground to pass the 50-hole sieve. The moisture is separately estimated in this sample also, so th^t all estimations can be calculated on coal as received. When coal analysis was first started in this laboratory volatile matter was determined on both samples, but as in no case were any great differences found, the determination on the fine (50-hole) sample was discontinued. For the estimation of specific gravity a special sample is taken from the tin, and that portion only is used which passes an 8-hole and is retained on a 16-hole sieve. Moisture and ash are separately estimated on this sample in order to get the dfensity of the dry coal, and an approximation to that of the pure coal. Moisture. — This is estimated in all three samples. One gramme of coal is heated in a Victor-Meyer toluene bath for one hour exactly. The coal is weighed off between clipped watch- glasses, heated uncovered, covered immediately on removal from the toluene bath, and allowed to cool in a desiccator. It is weighed half an hour after removal from the bath. This method has been used in preference to that of drying in vacuo with sulphuric acid in a Hem pel desiccator, as it is believed to be the more generally in use in other laboratories, although in many cases less moisture is found by this method. A discussion on this point is to be found in the Journ. Am. Chem. Soc. (loc. cit.). Du,plicate estimations should agree within 1 per cent. There seems no reason to recommend any change in the * Journ. Am. Chem. Soc, 1899, vol. xxi., p. 1,116. ANALYTICAL METHODS. I method -described (drying at 105° C. for one hour) unlpss it be that the drying should be carried out in a current of dry nitrogen or carbon dioxide, so as to prevent the possibility of the coal oxidising during the drying process. Some coals undoubtedly do oxidise in air at that tenaperature and will do so, though more slowly, even at ordinary temperatures. The use of well-fitting watch-glasses or shallow stoppered tubes (the iipper glass or stopper is, of course, removed whilst drying) is important, as many cOals are hygroscopic and rapidly gain weight on the balance after drying if left uncovered. These points are fully gone into in the Report of the International Committee on Analyses to the Eighth International Congress of Apjilied Chemistry at Few York, 1912, p. 77 (Belin Freres, Paris, 1912). Volatile Matter. — One gramme of coal is heated for seven minutes exactly in a platinum-crucible with well-fitting cover supported on a platinum-triangle over a bunsen giving a flame 20 cm,, high. The bottom of the crucible should be 8 cm. above the mouth of the burlier; gas-pressure should be 50 mm. of water. The particulars of the crucible used are: — Height, 40 mm. ; diam. at base 24 mm., at top 34 mm. Capsule cover. A cylinder of jclay or asbestos-board (of about 12 cm. diam.) should be used to prevent draughts from influencing the flame during the operation. Loss in weight minus moisture gives volatile matter.* Duplicates should agree within -15 per cent, on coals, with 15 per cent, volatile matter and under, and -30 per cent, on coals with over 15 per cent. The value found for volatile matter depends to some extent on the size of crucible, tightness of cover, strength of flame, &c. ; it is of importance therefore to work under as constant conditions as possible. With some coals at times a small explosion occurs after about one minute's heating, in which case the experiment should be discarded, otherwise too much volatile matter will be found. The cover of the crucible should fit so as to allow the egress of the volatile matter as easily as possible, but prevent the aix from getting at the coke more than can be prevented. Meade and Attixt suggested heating a second time under identical conditions and subtracting the second loae^ from the first. This was tried in several cases, but did not appear to offer any distinct advantage over the other method. Ash. — (See also under " Combustion.'') The ash left in the platinum-boat after combustion has invariably been taken as representing the ash in the coal. Of all the constituents ash is probably the least' accurately determinable (and hence oxygen also), a point that is gone into under " Accuracy of Coal Analyses " on page 38. * Some analysts report as " Volatile Matter " all the loss inoluding moisture, and as " Volatile Hydrocarbons " this loss minus moisture and haii the sulphur. A short discussion and criticism on the different terms used in reporting proximate analyses will be found in "Analyses of British Coals and Coke," 1907, p. V. (The Chichester Press, London). f Joum. Am. Chem. Soc, 1899, vol. xxi., p. 1,137. 8 THE COALS OF SOUTH WALES. Duplicates should agree within -1 per cent, on coals with less than 4 per cent, ash, and -2 per cent, on coals with more than 4 per cent. ash. Fixed Carbonaceous Residue.— This is obtained by subtract- ing the sum of the percentages of ash, moisture, and volatile matter from 100. Total Sulphur.— The method of M. W. & J. Atkinson has been used with only slight modification . The following descrip- tion of the method is taken from the report of the Commission on Coal Analysis of the American Chemical Society.* " One gramme of finely-ground coke or coal is mixed thoroughly with 5 grammes of dry sodium carbonate, spread evenly over the bottom of a flat or shallow platinum dish, and the latter placed on a rectangular rest made of clay pipe-stems inside 'a muffle, which though hot is still black. The tem- perature of the muffle should be raised gradually during half an hour to clear cherry-redness, and then kept at the lattei; tem- perature for 10 to 15 minutes. The sodium carbonate should not sinter or fuse. The mass should not be stirred. When the carbon is burned, usually in about 45 minutes in all, cool, digest with 100 to 200 c.c. of warm water, allow to settle, decant through a filter and wash twice by decantation, and then on the filter, adding a few drops of a solution of sodium chloride if the residue tends to pass through the filter. The filtrate is acidified with 12 c.c. concentrated hydrochloric acid, and precipitated with barium chloride." To avoid any possibility of all the sulphur not being oxidised to sulphate before acidifying, a little (about 10 c.c.) bromine water has always been added after filtering and before acidify- ing. It is usually necessary to heat for longer than the 45 minutes to burn off all the carbon. With these slight differences the method has been adhered to with most satisfactory results. The muffles used have been Fletcher gas-muffles, Nos. 461 and 661. Blind experiments have always been made simultaneously with and separately from determinations of sulphur in coal, and in no case has any' appreciable amount of sulphur been obtained from the gas. As it is almost invariably necessary to correct for traces of sulphur contained in the sodium carbonate used, it is always as well to make a blind experiment with each batch of sulphur-estimations. Duplicates should agree within -1 per cent. For a discussion on determination of sulphur in coal reference should be made to a paper by Dr. M. HoUinger in Z. Angew. Chem., xxi. (1909), pp. 436, 493; Brunck's'cobalt- oxide method is there recommended for total sulphur, and a modification of Sauer's method for combustible sulphur. The original method as described above has been adhered to in our recent analyses to secure uniformity with the previous work. No opportunity has occurred of carrying out comparative tests of Atkinson's method and that recommended by Dr. Hollinger. * 76., p. 1,116. The original appeared in the Journ. Chem. Ind., 1886. ANALYTICAL METHODS. » Sulphur in Ash. — This is obtained from tlie ash from the combustion. The ash is transferred to a dish, hydrochloric acid added, evaporated to dryness, taken up with hydrochloric acid and hot water, filtered, and the sulphur in the filtrate pre- cipitated with barium chloride. The amount of sulphur obtained here, subtracted from the total sulphur, gives the Combustible Sulphur. Nitrogen. — Estimated by Kjeldahl's method. 1 gram m e of coal is heated with 20 c.c. strong sulphuric acid, 8 grammes dry potassium sulphate and a bead of mercury, till colourless. Allow to cool, pour into a flask of about 1,000 c.c. capacity con- taining about 200 c.c. water, rinse out, etc., and add 80 c.c. of a 50 per cent, sodium hydrate solution and 20 c.c. of a 5 per cent, potassium-sulphide solution. Distil (using a good splash-head), collecting in 20 c.c. ^ acid. Titrate back with ^ alkali, using methyl orange as indicator. The mercury, and hence the potassium sulphide, may be dis- pensed with,* the only difference apparently being that with the mercury shorter heating is needed. Blind experiments should be m.ade and the correction applied. Duplicates should agree within -1 per cent. In the recent analyses made in the Government Laboratory a slight modification tending to greater accuracy was adopted in carrying out the nitrogen determination. The details of the method as actually employed were as follows : — To I gramme of coal 30 c.c. of pure concentrated sulphuric acid containing 1 gramme of salicylic acid were added, the vessel being kept cool by immersion in water during the addi- tion of the acid. Five grammes of sodium thiosulphate were then added cautiously, and afterwards 7 grammes of potassium sulphate and a crystal of copper sulphate. The mixture was then heated, cautiously at first to avoid frothing, and then strongly until all the coal was, decomposed. The solution was then cooled and distilled with excess of soda and a little sodium N sulphide in the usual way into 25 c.c. of j^ sulphuric acid. The excess of soda was determined by adding to the solution 10 c.c. of a 10 per cent, solution of potassium iodide and 5 c.c. of a saturated solution of potassium iodate — the liberated iodine was determined as usual. A sharper end-point was obtained by this method than by that formerly used. Duplicate determina- tions agreed to within 0-05 per cent. Combustion. — (Carbon, hydrogen and ash.) Jena-glass com- bustion-tubes, about 110 cm. long and 12-15 mm. internal diameter, are best used. They are filled as follows : — 10 cm. space at each end. 6 to 8 cm. copper-oxide roll. 16 to 20 cm. space for boat. 45 cm. copper-oxide. 8 cm. lead-chromate pumice. 10 cm. silver spiral. * Lunge. " Chem. Techn. Untersuchungsmethoden," 4th ed., vol. i., p. 228. 10 THE COALS OF SOUTH WALES. The furnace should be about 36 inches long ; that used in this laboratory is a Fletcher combustion-furnace No. 2. The boat is of platinum, 10 cm. long. The purifying train (one for air and one for oxygen with a three-way tap so that the gas can be changed at once) consists of an Emmerling's absorption-tube and a washbottle with 1 in 2 potash, one washbottle with .con- centrated sulphuric acid, followed by two U-tubes filled with pumice saturated with concentrated sulphuric acid.* Between the three-way tap and the combustion-tube a small sulphuric acid washbottle is placed (so that the rapidity of the gas-current can be easily watched), followed by a small mercury-trap. ' For the collection of the water a U-tube filled with pumice saturated with sulphuric acid is used. Before each combustion this is filled with acid overnight, the acid being drained off just before weighing. Geissler bulbs, with an 8 cm. drying-tube filled with freshly-crushed potash, are used to absorb the carbonic acid, followed by a small sulphuric acid U-tube to absorb the last traces of moisture, and finally a protecting tube of sulphuric acid pumice. It is hardly necessary to state that bulbs and tubes are refilled before each combustion. The following points may be of use, although it is unneces- sary to describe the combustion in detail. The weight of dry- coal is as near -5 gramme as possible, this having been found the most convenient amount to work with for accuracy. The finely powdered coal (50-hole sample) should be used, and spread in as thin a layer as possible in the boat. The boat and coal should be dried for one hour exactly in the toluene bath immediately before required. When the boat, after final weighing before combustion, is placed in the combustion-tube, it should' rest on a strip of platinum-foil ; this j)revents any chance of its sticking to the tube, and diminishes the chance of any copper oxide adhering to it. Before commencing to heat the boat the oxygen is turned on in a gentle current. The copper oxide and silver spiral should be at a bright-red heat, and the copper oxide roll and lead chromate pumice a dull red heat. When these are at the required temperature the boat is gradually heated and the combustion carried out in the usual way. Duplicates should agree within : — Hydrogen -1 per cent. Carbon -2 „ It is irnportant for the copper oxide to be hot enough before the coal is heated, as possibly methane is amongst the first of the volatile products to come off, and it is well known that this gas requires a high temperature for combustion. In two of the earlier combustions made in this laboratory there seemed some reason to suspect that some methane had escaped combustion, as the difference between the carbon, and hydrogen of the lower to the higher results gave the ratios of C : H = l : 3-5 and C :H = 1 : 3-8, whilst in each case the ash agreed. On repeating these combustions concordant results with the higher values were , * The pumice should be ignited with sulphuric acid before use to expel chlorides, etc. ^ ANALYTICAL METHODS. 11 obtained in eacli case. Another possible source of error, wben duplicates agree in the hydrogen but not in the carbon and ash, may be due to incomplete combustion of the carbon. This was found to have occurred on more than one occasion, in each case the coal containing over 5 per cent, of ash, and having a high caking-power. It was, indeed, owing to this that a boat 10 cm. long has since been used instead of one of the usual size, as the hall gramme of coal can be spread out into a thin layer, thus reducing the chance of incomplete combustion. The following example illustrates this point. A boat 5 cm. long was used, and the caking power of the coal was about 45 : — 1 2 3 c 79-72 79-97 80-13 H 4-75 4-76 4-82 Ash 8-38 8-12 7-98 The liydrogens all agree within the limit of -1 percent., but the carbons vary. . Nos. 2 and 3 are within the -2 limit, but No. 1 is low. On looking at the ashes, however, it will be seen that the sum of ash and carbon is in each case the same. It has been suggested that one cause of low carbon-results might be due to some carbon monoxide escaping complete com- bustion to dioxide. At Mr. Seyler's suggestion a small wash- bottle, containing dilute sodium-palladium chloride solution, was placed behind the protecting IF-tube, so that all gases from the combustion-tube, not previously absorbed by the U-tube and potash-bulbs, must pass through the solution, and thus render it possible to detect monoxide. On no occasion has there been any indication whatever of its presence, in spite of one or two low carbons which could not be accounted for, except by assum- ing a slight leak between TJ-tube and potash-bulbs, though none could be detected. Although several papers have appeared suggesting modifica- tions in carrying out combustions since the first edition of this Memoir was written, there is no reason to believe that more accurate results combined with rapidity of working can be obtained than by the method originally adopted. Caldng Power. — This determination is not capable of any great accuracy, but is sometimes of use for comparative pur- poses. The coal is powdered to pass the 50-hole sieve, and is mixed with varying proportions of dry sand, which passes the 40-hole and stops on the 50-hole sieve; the weight of the two together is 25 grammes for each experiment. The charge is placed in a platinum-crucible, and heated exactly as for an estimation of volatile matter. After cooling, the cake is care- fully removed from the crucible, placed on a flat surface, and a 5dO-gTamme weight carefully placed on it. When the cake just crushes the caking-power is reached. The caking power is expressed as the weight of sand per unit weight of coal, thus : — B 12 THE COALS or SOUTH WALES. Sand. Coal. Caking Power. 20-0 22-5 24-0 50 2-5 10 4 9 24 etc. It is important that the coal be as fresh from the pit as possible, as in many cases the caking-power has been found to decrease by keeping. Specific Gravity. — Estimated in a specific-gravity bottle, on about 5 grammes of the special sample already described. Air is removed by boiling. Moisture- and ash-determinations are specially made on this sample, so as to give data for calculating approximately the density of the dry ash-free coal. To correct for ash, either -01 may be deducted from the specific gravity for each per cent, of ash, or the specific gravity of the ash may be specially estimated and correction applied. In either case, the final result of correcting can only be regarded as approximate. In the analyses made at the Government Laboratory the specific gravity determinations were carried out at 15-5° C, using 150 grains of coal and a pyknometer holding 1,000 grains. The air was removed by evacuating the pyknometer, and check- determinations were made by boiling in the manner described above. As an example of a possible error in the correction, where the specific gravity of the ash has been determined : — If the specific gravity of a coal containing 95 per cent, of pure coal and 5 per cent, pyrites fmoisture and other ash-constituents are omitted for the sake oi simplicity) be 1-300, taking the specific gravity of pyrites as 5-0, the specific gravity of the pure coal would be 1-251. But as 5 per cent, pyrites would become on ashing (assuming the reaction to be quantitative) 3-33 per cent. Fe^Og, and taking the specific gravity of Fe^Oj as 5-1, the specific gravity of the pure coal as found would be 1-268. As it happens, in this case the deduction of -01 for each per cent, of ash would be the nearer, but in the case where the ash as obtained by analysis is the same as that really contained in the coal, the direct method would probably give the more accurate figure. ANALYSES. 13 Analyses of the Coals of South Wales, from all Sources. Abhremations, Geol. Surv. — Samples collected and analysed by the Geological Survey in the years 1901-9. G.S. (0. A. S.) — 'Samples collected by the Geological Survey, but analysed by Mr. C. A. Seyler in the year 1905. Grov. Lab. — Samples collected by the Gteological Survey but analysed at the Government Laboratory in the year 1914. Adm. Kept. — " Report on the Coals suited to the Steam Navy," by Sir H. T. de la Beche and Dr. Lyon Playfair. 1st Rep., dated 1848 ; 2nd Rep., 1849 ; 3rd Rep., 1851. The first Report was printed in Mem. Oeol. Survey, vol. ii., Part 2, pp. 539-630, 1848. Percy, 37, p. 325.— " Metallurgy," by John Percy, M.D., F.R.S., P.G.S., Ed. 1875. The first number refers to the number of the analysis, the second to the page. S.W. Inst. E. — ^Transactions and Proceedings of the South Wales Institute of Engineers. C.G. — Colliery Chiardian. A. B.C. and C. — " Analyses of British Coals and Cokes collected and com- pared." Reprinted from the Colliery Guardian. (First issue in parts, not dated ; 2ud issue in 1907.) Inst. M.E. — Transactions of the Federated Institution of Mining Engineers. Inst. C.E. — Proceedings of the Institution of Civil Engineers. C.A.S. — Analyses made and communicated to the Geological Survey by Mr. C. A. Seyler." Per C.A.B. — Analyses communicated to the Geological Survey by Mr. Capel A. Branfill. The carbon, hydrogen, oxygen and nitrogen are expressed in percentages calculated for the " pure coal," i.e. for the coal after deduction for moisture, ash, and combustible sulphur. Thus in analysis 1, C. 88-66 + H. 4-89 + 0. 4-90 -I- N. 1-55=100. n The TT ratio is the relation of carbon to hydrogen. Thus in Analysis 1, 88-66 4-89 1813. The percentage of Volatile matter is calculated on the coal exclusive of moisture and ash. The fuel-ratio is the relation of fixed carbonaceous residue to volatile matter. Thusin Analysis 1, ^""t!"'^" = 2-25. •' 30-80 The specific gravity is determined on the coal as received from the colliery. The ash is expressed in percentage of the dry coal, i.e. coal dried at 105°C. b2 14 THE COALS OF SOUTH WALES. No. on Plates 1 and 1-inoh Map. Local Name of Vein. CoUiery. Authority. 3-7. 1 232 Black Geological Survey 2 249 ,, JJ SJ 3 232 Top Coal, Rock tt »> 4 249 Black J> »» 5 248 Nine Foot ... »J » 6 231 Nine Foot »» y> 7 232 Ras-las ... tt >» • ■• 8 232 Rock or Horn 9 248 Nine Foot ;; {dA.s.) ::: 10 229 Big ... j.» 93 11 230 Stanllyd 12 229 Big ... ... ... if 11 •" 13 229 Stanllyd ... 14 231 Big ... >* fJ 15 247 Four Foot ... ... ... »J »J • • ■ 16 230 Big ... >» >> ••* 17 230 Stanllyd >» » 18 248 Cribbwr >» J> ' • • 19 231 Nine Foot 20 249 Cwm Frood Rook Near Varteg Iron Co.'s Works Adrn'Rept. i.',' pp. 33, 62 21 231 Gadley Nine One-third mUe Adm. Rept. ii., pp. 35, Foot W. of Aberdare 54 22' 231 Ras-laa Dowlais Percy, 37, p. 325 23 248 Nine Foot Llynfi ... Percy, 73, p. 332 24 231 Nine Foot Bute Pit, Hir- wain Percy, 83, p. 332 25 231 Nine Foot PwlUaron, Glyn Neath Percy, 95, p. 333 26 231 Big Gwaunclawdd S.W. Inst. E., xxi, p. 503 27 247 Nine Foot Morfa S.W. Inst. E., xxi, p. 519, No. 422 28 249 Black Abercarn S.W. Inst. E., xxi, p. 519, No. 224 29 230 Big ... C.A.S 30 230 Big 31 230 Big 32 230 Big „ 33 230 StanUydBig ... ,, 34 2.'?0 Big or Nine Foot Pontyberem ... C.G., Ixx, p. 1,212, and Ixxxiv, p. 1,081 35 249 Black Tirpentwys Coal Co. A.B.C. & C. (1907), p. 131 36 232 Black LlanhiUeth A.B.C. & C. (1907), p. 129 37 231 Big Ynyscedwyn ... Inst. M.E., XX (1900-1), p. 159 38 230 Middle Vein, Lower Stanllyd C.A.S 39 232 Big Blaina Percy, 8, p. 322 40 231 Big Abercraf A.B.C. & C. (1st Ed.), p. 126 * See note (1) at end of Table. ANALYSES. 15 No. on C H Plates 1 and C. H. 0. N. Volatile Matter. Fuel- ratio. Sp. Gr. Ash. 3-7. ratio. 1 88-66 4-89 4-90 1-55 18-13 30-80 2-25 1-33 6-4 2 88-24 5-24 4-92 1-60 16-84 34-41 1-91 1-31 5-3 3 88-30 5-45 4-83 1-42 16-20 36-10 1-77 1-33 7-1 4 87-49 5-33 5-76 1-42 16-41 36-50 1-74 1-335 6-8 5 91-58 4-51 2-36 1-55 20-30 17-87 4-60 1-34 2-8 6 93-15 3-59 1-89 1-37 25-95 11-59 7-63 1-41 3-8 7 91-64 4-30 2-74 1-32' 21-31 16-65 5-00 1-365 4-7 8 88-61 6-29 4-80 1-30 16-75 33-03 2-03 1-303 3-9 9 91-40 4-78 2-62 1-20 19-12 17-56 4-69 1-33 3-2 10 93-86 3-44 1-50 1-20 27-28 5-67 16-64 1-392 21 11 94-37 3-49 -98 1-16 27-04 5-42 17-46 1-440 2-7 12 93-77 3-74 1-26 1-23 25-07 6-47 14-46 1-409 2-4 13 94-43 3-33 1-27 -97 28-36 5-30 17-84 1-434 1-1 14 93-56 3-57 1-68- 1-19 26-21 5-90 15-95 1-437 3-9 15 88-51 5-02 ■ 5-24 1-23 17-63 28-08 2-56 1-315 2-3 16 94-19 3-43 1-18 1-20 27-61 5-30 17-87 1-431 1-9 17 94-06 3-47 1-26 1-21 27-11 5-71 16-52 1-444 3-6 18 87-93 5-39 5-06 1-62 16-31 29-86 2-35 1-288 -9 19 92-65 3-96 1-98 1-41 23-40 8-52 10-74 1-435 6-2 20 88-65 6-29 3-86 1-20 14-09 33-20 2-01 1-255 6 21 91-89 4-59 2-38 1-16 20-02 14-22 6-03 1-333 5-3 22 90-87 91-37 4-65 4-93 3-03 1-45 19-54 18-53 20-05 3-99 — 20 23 3-70 2-4 24 93-62 4-11 2-27 22-78 10-02 8-98 — 1-8 25 93-79 3-86 2-35 24-30 6-25 15-00 — 2 26 93-37 3-43 3-20 27-22 5-40 17-62 — 2-2 27 86-30 5-34 8-35 16-16 30-40 2-29 — 5-6 28 86-19 5-41 8-40 15-93 31-40 2-18 — — 29 93-92 3-55 2-53 26-49 5-00 19-00 1-6 30 93-70 3-63 2-67 25-81 5-17 18-34 — 1-0 31 93-86 3-83 2-31 24-51 5-76 16-36 — 2-0 32 93-96 3-74 2-30 25-12 5-50 17-18 — 1-2 33 94-21 3-75 2-04 25-12 5-75 16-39 — 1-8 34 95-33 90-74 3-47 4-84 1-20 27-47 18-73 , . 1-34 1-1 35 3-43 -99 6-3 36 86-85 93-21 4-77 3-57 7-28 1-10 18-21 26-11 8-50 10-76 — - 2-2 37 3-22 1-6 38 93-82 87-14 93-91 3-81 6-49 3-70 2-37 24-62 13-43 25-38 5-83 6-08 16-15 15-44 — — 39 4-81 1 1-56 4-0 40 2-39 20 16 THE COALS OF SOUTH WALES. No. on Plates 1-inoh Local Name of 1 and 3-7. map. Vein. Colliery. Authority. 41 231 Big Ystradgynlais... A.B.C. & C. (1st Ed.), p. 123 42 248 Yard Aberaman C.G., Ixxi., p. 541 43 247 Average of Four and Six Foot Llanmorlaia ... „ p. 1,015 ... 44 230 Stanllyd Park and Blaina A.B.C. & C. (Ed. 1907), p. 367 45 232 Old Geological Survey 46 232 Old or Lower Four Foot Nantyglo and Blaina Percy, 122, p. 569 47 231 Peacock C.A.S 48 230 Little [Brass] ... 49 230 Peacock , 50 230 Brass Cwmllynfell ... Adm. Rept., i., pp. 34 &58 51 230 Peacock ... C.A.S 52 231 Peacock Gwaimclawdd A.B.O. & C. (1st Ed.), p. 123 53 230 Peacock ... ... ... C.A.S 54 248 No. 2 Rhondda S.W. Inst. E., xxi, p. 511 55 248 Rock Vawr ... Bronbil Adm. Rept., ii., pp. 21 &51 56 248 No. 2 Rhondda ... C.A.S 57 249 Rook Machen Adm. Rept., iii., pp. 39 &51 58 248' No. 2 Rhondda C.A.S 59 248 Rock Fawr ... Bronbil Adm. Rept., iii, pp. 43 &52 60 230 Upper or Pen-y- Graig Cwm Che Percy, 130, p. 569 61 248 No. 2 Rhondda- Glyn Corwg ... Percy, [the mean of] 118-120, p. 569 62 247 Penlan Gas-coal Penlan A.B.C. & C. (1st Ed.), p. 82 63 232 Meadow ... Geological Survey 64 232 Mynydd Black Blaenserchan ... A.B.C. & C. (Ed. 1907), p. 129 65 232 Meadow Geological Survey 66 247 Cribbwr Morfa S.W. Inst. E., xxi, p. 516. 67 231 Four Foot or Cornish Abercraf A.B.C. & C. (1st Ed.), p. 126 68 231 Cornish Pwllfaron Percy, 121, p. 569 ... 69 247 Four Foot Morfa S.W. Inst. E., xxi, p. 519. 70 230 Wernfiraith ... Primrose C.G., Ixxi, p. 1,015 ... ANALYSES. IT No. on Plates 1 and 3-7. C. H. 0. N. C H ratio. Volatile Matter. Fuel- ratio. &p. Gr. Ash. 41 93-88 3-65 1-86 — -62 25-72 2-1 42 43 94-32 3-68 — — 26-63 10-73 24-00 5-16 8-32 317 18-42 — 2-4 2-0 44 2-00 1-1 45 87-93 90-74 5-30 .6-23 6-50 1 1-27 16-69 17-36 31-48 22-72 2-18 3-40 1-320 5-0 46 4-03 6-0 47 48 49 94-02 94-19 93-67 93-60 93-39 93-70 3-96 3-58 3-73 3-54 3-66 3-90 2-30 2-23 2-60 23-74 26-31 25-11 26-44 25-52 24-03 7-20 5-12 6-84 7-21 5-26 6-34 12-88 18-53 16-12 12-87 18-04 14-76 1-376 2-4 1-6 1-4 50 2-64 1 ■22 1-6 51 52 2-95 2-40 1-8 2-3 63 54 94-02 89-74 85-23 91-78 75-00 92-64 84-78 93-58 3-66 5-67 4-80 5-13 5-15 4-74 6-67 4-05 2-32 4-59 25-69 15-83 17-76 17-89 14-66 19-54 16-22 23-11 5-76 27-60 40-56 18-31 36-19 17-33 43-26 7-62 16-36 2-62 1-47 4-47 1-76 4-77 1-31 12-12 1-292 1-297 1-301 2-2 55 9-35 1 -62 7-6 56 3-19 6-4 67 18-85 1 I -00 3-8 58 2-62 6-6 59 8-94 2- 1 ■71 4-3 60 37 6-3 61 91-66 4-86 3-49 18-91 19-56 33-50 4-12 2-13 1-257 4-6 62 — — 2-1 63 64 87-97 87-52 5-26 5-16 5-26 6-26 1-52 1-06 16-72 16-96 34-34 1-91 1-330 8-1 3-1 65 87-16 87-50 5-42 5-16 5-83 1-59 16-08 16-99 33-84 28-90 1-95 2-46 1-326 6-5 66 7-36 1-3 67 93-69 3-74 2-67 25-05 6-73 13-86 — 2-0 68 93-83 3-96 2-22 23-75 6-78 13-75 — 4-1 69 85-20 5-40 9-40 16-78 30-60 2-27 — 2-6 70 92-45 4-80 2-75 19-26 ■ " " 3-0 18 THE COALS OF SOTJTH WALES. No. on Plates 1 and 1-inch map. Local Name of Vein. Colliery. Authority. 3-7. 71 247 Four Foot Near Morriston Adm. Rept., i., pp. 32 &60 72 249 Mynyddislwyn ... Geological Survey 73 249 Bedwas Vein ... Bedwas Adm. Rept., i., pp. 40 &63 74 247 Five Foot Mynydd-Newydd S.W. Inst. E., xxi, p. 508 Adm. Rept., i, pp. 29 & 75 247 Penylilia or Five tt tt Foot 61 76 247 Clyndie [Clyn- du] or Five Foot Llangyfelach ... Adm. Rept., i, pp. 24 &61 77 231 Six Foot Glyncastle Inst. M.E., xii, p. 238 ; also A.B.C. & C. (Ed. 1907), p. 386 78 248 Two-foot-nine Blaen Rhondda Percy, 98, p. 333 79 248 jj >» Dunraven Percy, 101, p. 333 80* 231 Gadley Four l-3rd mile w. of Adm. Rept., ii, p. 35 Foot Aberdare &53 81 248' Upper Four Foot Ffaldau S.W. Inst. E., xxi, p. 508 ; C.G., Ixx, p. 639 82 248 »> It Ynysyfaio C.G., IxxV, p. 570, and liTTxiv, p. 1,081 83 248 »» »» Dunrav"en Percy, 102, p. 333 ... 84 248 »» >» Blaen Rhondda Percy, 99, p. 333 85t 231 »j >> Dowlais Percy, 36, p. 325 86 248 Four Foot of Dyffryn Aberdare VaUey Adm. Rept., i, pp. 25 & 61 87 232 Four Foot Ebbw Vale Iron- works Adm. Rept., i, pp. 42 &64 88 231 It »» Hill's Plymouth Merthyr Adm. Rept., ii, pp. 42 &65 89 248 Upper Four Foot Aberaman Adm. Rept., iii, pp. 26 &49 90 232 Ell Blaina Percy, 6, p. 322 91 230 Graigola Primrose C. G., Ixxi, p. 1,015 ... 92 232 Three Quarter Blaina Percy, 7, p. 322 93 232 Three Quarter (top vein) Nantyglo and Blaina Percy, 123, p. 569 ... 94 249 Three Quarter ... ... ... Geol. Surv 95 232 Three Quarter Nr. Varteg Iron Adm. Rept., i, pp. 30 & Rock Co.'s Works 62 96 232 Three Quarter ... ... Geol. Surv. 97 232 ft it ... ... ... ,, ... ... 98 230 Six Feet Graigola Mer- thyr C. G., Ixxi, p. 1,015 ... 99 230 Six Feet Primrose S.W. Inst. E.,xxi, p. 508 100 247 Six Feet (part of) Mynydd-Newydd S.W. Inst. E., xxi, p. 513 * See note (1) at end of Table. f See note (2) at end of Table. ANALYSES. 19 No. on Plates 1 and 3-7. C. 1 H. i 0. N. C H ratio. VolatUe Matter. Fuel- ratio. '£: Aah. 71 91-81 4-66 1 3-34 -19 19-70 18-10 4-53 1-31 3-4 72 73 86-94 90-01 91-66 88-66 5-64 6-71 4-87 6-03 5-84 1-67 1-58 1-61 15-41 13-41 18-82 14-70 37-52 30-41 18-80 26-04 1-68 2-29 4-32 2-84 1-336 1-32 1-31 7-3 6-9 74 3-47 6-4 75 3-68 1-63 3-2 76 91-18 3-97 4-85 trace 22-97 15-97 5-26 1-358 6-1 77 93-63 94-11 93-35 93-77 91-31 91-86 92-74 90-92 92-93 4-01 4-19 4-15 4-64 4-95 3-93 3-96 4-51 4-91 1-91 -45 23-35 22-46 22-49 20-21 18-45 23-37 23-42 20-16 18-93 11-03 11-16 11-22 18-78 12-02 10-61 10-26 16-23 8-06 7-96 7-91 4-33 7-32 8-42 8-75 5-16 1-327 1-29 1-326 1-3 78 79 1-70 2-50 2-8 1-4 80 -65 1 -94 4-9 81 3-74 -9 82 — 1 — 1-0 83 84 4-! 3-. 21 JO 3-8 4-8 85 86 3-31 -63 1-26 1-53 1-2 3-3 87 92-10 5-28 -40 2-22 17-44 22-84 3-38 1-275 1-5 88 91-44 4-13 3-95 -48 22-14 18-19 4-50 1-359 2-4 89 93-40 4-39 -97 1-24 21-27 15-22 5-57 1-305 1-5 90 84-42 92-73 86-25 89-81 87-81 87-19 5-48 4-64 5-90 5-11 5-09 5-72 8-41 1-69 15-41 19-98 14-62 17-58 17-25 15-24 25-03 32-39 42-12 2-99 2-09 1-37 1-314 1-34 1-5 91 2- 83 1-72 4-7 92 613 2-5 93 5-08 4-2 94 95 5-64 5-85 1-46 1-24 6-2 11-0 96 97 98 86-63 87-20 91-70 90-75 5-13 5-10 4-80 4-73 6-85. 6-36 1-39 1-34 16-89 17-10 19-10 19-19 33-92 32-78 12-53 15-70 20-30 1-95 2-05 6-98 5-37 3-93 1-307 1-327 4-6 7-0 1-7 99 100 3- 4- 50 52 4-6 6-0 20 THE COALS or SOUTH WALES. No. on Plates 1 and 3-7. 1-inch map. 101 102 103 104* 105 106 107 108 109 110 111 112 list 114 115 116 117 118 119 120 121 122 123t 124 125 126 127 128 § 129 247 247 230 247 246 247 247 230 232 232 249 230 230 247 247 247 247 247 247 247 247 247 249 230 248 248 248 230 231 Local Name of Vein. Colliery. Binea or Loughor Kery Brynddwey .. Graigola Ward's Fiery.. Fiery Graigola Brynddwey . . Graigola Red Big »» ... .. Tregloin Cadoxton Hughes Slatog Rotten or Bodor Curly ... Hedley's Hughes J, ... Three Foot ... Charcoal Lower or Welsh No. 3 Rhondda Graig Graig Red Binea Farm ... Neath Abbey Ynysymond ... IJ mUea E. of Uanelly Old Castle ... BirchgroVe Neath Waun-y-ooed... Tirpentwys ... Cadoxton Weigfawr Cwrt-y-Bettws « Weigfawr Mynydd-Newydd Abercarn Cwm Clio Penrhiw Dunraven ... Blaen Rhondda PwUbaoh Dillwjni Authority. Adm. Rept., i, pp. 28 & 59 Adm. Rept., ii, pp. 13 &50 Adm. Rept., i, pp. 31 & 57 Adm. Rept., i, pp. 27 & 58 Adm. Rept., i, pp. 26 & 58 Adm. Rept., iii, pp. 21 &48 Inst. C.E., viii, p. 101 Percy, 89, p. 333 Geol. Surv. A. b'.'c. &C. (Eci'lOof), p. 132 C.A.S Adm. Rept., iii, pp. 16 &47 C.A.S S.W. Inst. E., xxi, p. 523 S.W. Inst. E., xxi, p. 519 S.W. Inst. E., xxi, p. 519 S.W. Inst. E., xxi, p. 508 C.G., Ixxi, p. 1,015 ... S.W. Inst. E., xxi, p. 523 S.W. Inst. E., xxi, p. 508 Adm. Rept., iii, pp. 33 &50 Percy, 131, p. 569 A.B.C. & C. (Ed. 1907), p. 392 Percy, 100, p. 333 Percy, 97, p. 333 S.W. Inst. E., xxi,p. 506 A.B.C. & C. (Ed. 1907), p. 390) • * See note % See note (4) at end of Table. (6) at end of Table. t See note (6) at end of Table. § See note (7) at end of Table. ANALYSES. 21 No. on Plates land 3-7. C. H. 0. N. C H ratio. Volatile Matter. Fuel- ratio. §?: Ash. 101 92-61 4-84 106 i-4a 19-13 12-39 7-08 1-304 4-0 102 93-57 5-31 — 1-12 17-62 40-00 1-50 1-310 3-6 103 88-12 3-99 7-46 -43 22-09 14-99 5-67 1-30 3-2 104 94-68 4-23 — 1-09 22-38 — — 1-344 7-0 105 90-14 5-03 3-48 1-35 17-92 20-77 3-82 1-289 2-6 106 88-96 4-38 5-89 •77 20-31 15-59 5-41 1-360 4-4 107 85-33 93-08 87-77 87-81 90-58 9416 5-32 4-47 4-97 512 5-39 3-66 7-66 1-69 16-04 20-82 17-66 17-15 16-81 25-73 13-96 31-08 32-97 5-20 6-16 2-22 2-03 18-23 1-325 1-338 1-319 51 108 2- 45 1-9 109 110 111 5-94 5-65 3-39 1-32 1-42 -64 3-4 7-2 5-0 112 2-] L8 2-0 113 93-79 92-64 3-63 4-58 2-58 25-84 20-23 5-41 18-67 17-48 4-36 I 1-378 4-3 1-3 114 1-67 1 Ml 3-6 115 116 92-46 83-63 4-36 5-28 3-18 11-09 21-16 15-84 11-74 35-70 7-52 1-80 — 2-2 4-4 117 85-69 5-81 8-50 14-75 33-60 1-97 — 3-3 118 85-93 5-92 8-15 14-52 37-70 1-65 — 5-5 119 91-69 4-59 3-72 19-98 14-75 5-77 — 4-4 120 121 91-52 77-40 4-71 4-67 3-77 17-93 19-43 16-57 61-50 -94 — 4-0 27-5 122 91-46 5-02 3-49 18-22 19-70 4-08 — 4-1 123 84-56 93-71 88-44 91-66 92-57 6-57 3-69 5-32 4-71 4-72 8-07 1 -80 12-87 25-40 16-62 19-46 19-61 32-26 7-44 25-40 19-61 16-35 2-10 12-44 2-94 4-10 5-12 1-334 2-0 124 2-60 4-4 125 5-11 1 113 1-6 126 127 3-63 2-71 3-4 3-3 128 92-48 93-56 403 3-48 3-49 22-95 26-89 6-04 15-56 ( 1-7 5-5 129 2-21 1 -75 3-9 1 22 THE COALS OF SOUTH WALES. No. on Plates 1 and 3-7. 1-inoh map. Local Name of Vein. Colliery. Authority. 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 230 230 230 230 230 230 230 230 230 230 230 230 230 230 229 229 229 248 248 248 248 248 247 247 247 247 247 247 247 247 247 230 231 230 231 230 230 230 Red Pontyberem No. 1 [Gras-uohaf] Clynhebog- [Lower Pump- quart] Middle liower Lower Trioh- wart New Cross Hands [Lower Pumpquart] Lower Pump- quart Big Drap Green Cae David Six Foot - ... »» .. ■ Duffryn Yard Five Foot (top) (middle) (bottom) (top ... (middle) (bottom) (top ... (middle) (bottom) Peacock Big Peacock Red Big Peacock Big Cwm Gtors Cawdor Ynysygeinon Pontyberem New Cross Hands Ty-chwjrth Dunraven Llynfi Brynhenllys . Ynyscedwyn . Gilfach Dillw3Ti Gwauncaegurwen Garnant C.A.S A.B.C. & C. (Ed. 1907), p. 403 C.A.S S.W. Inst. E., xxi, p.506 S.W. Inst. E.,xxi, p. 506 C.A.S A.B.C. & C. (1st Ed.), p. 58 A.B.C. & C. (1st Ed.), p. 58 C.A.S A.B.C. & C. (1st Ed.), p. 83 C.A.S. Percy, 72, p. 332 Percy, 103, p. 333 Percy, 74, p. 332 Percy, 75, p. 332 Percy, 77, p. 332 Geol. Surv. Per C.A.B. ANALYSES. 2c No. on Plates 1 and C. H. 0. N. C H Volatile Matter. Fuel- ratio. I;: Ash. 3-7. ratio. 130 93 03 3-51 3-46 26-50 7-73 11-94 — 3-6 131 94-08 3-79 2-13 24-85 6-48 14-43 — 2-7 132 93-39 4-09 2-52 22-83 7-39 12-53 1-9 133 93-42 4-02 2-56 23-24 6-60 14-38 . 2-8 134 92-58 3-91 3-50 23-68 7-70 11-98 . 3 135 93-33 3-93 2-74 23-75 6-53 14-31 2-0 136 — • — — ^ 6-39 17-54 — 1-7 137 — — — — 6-54 17-04 — •9 138 94-31 3-64 2-05 25-91 5-24 18-08 1-7 139 94-09 3-58 2-33 26-28 6-12 18-63 1-7 140 94-1 3-6 2-3 26-14 5-10 18-61 — 2-6 141 93-87 3-41 2-72 27-53 3-83 26-1 — -8 142 93-00 94-38 93-83 92-59 93-98 3-68 3-14 3-74 4-54 3-88 3-32 25-27 30-06 26-09 20-39 24-22 5-20 5-17 6-72 6-71 18-28 18-19 13-87 13-90 -{ 1-1 143 1-16 1 -87 -8 144 2-43 1-4 3-3 145 1-30 1 1-57 1-4 146 2-14 2-4 147 87-99 5-64 6-37 16-60 34-36 1-91 — 4-2 148 92-73 3-95 3-32 23-48 12-03 7-31 30 149 91-25 4-84 3-91 18-85 20-17 3-96 — 2-0 150 89-76 4-92 5-33 18-24 23-33 3-29 . — . 3-9 151 90-53 92-65 4-98 4-45 4-49 18-18 20-81 23-17 17-63 3-32 4-67 1-366 2-6 152 1-30 1-60 6-4 153 90-58 4-33 3-61 1-48 20-89 19-55 4-12 1-358 6-1 154 91-49 4-46 2-49 1-57 20-68 17-75 4-63 1-332 5-1 155 90-91 4-79 2-70 1-60 18-98 22-71 3-40 1-337 6-2 156 88-64 4-72 5-00 1-64 18-77 27-21 2-67 1-365 8-4 157 89-98 4-82 3-54 1-66 18-67 23-62 3-23 1-321 6-2 168 92-40 4-38 2-04 1-18 21-10 16-47 6-07 1-369 5-9 159 91-36 4-32 2-73 1-59 21-15 17-70 4-66 1-366 5-7 160 90-48 9213 4-34 3-76 3-66 1-52 20-86 24-54 15-99 5-26 1-353 5-6 161 4-11 1-4 162 92-46 3-20 4-34 28-87 _ — — 1-6 163 93-92 93-42 94-49 3-57 3-39 3-67 2-51 26-26 27-54 25-77 9-00 1011 — 1-0 164 1-65 1 1-54 1-8 165 1-84 1-7 166 93-80 3-16 3-04 29-64 — . — . — 2-3 167 9317 2-12 4-71 43-85* ""- — ' — -4 * See footnote on p. 63, 24 THE COALS OF SOUTH WALES. No. on Plates 1 and l-inoh map. Local Name of Vein. Colliery. Authority. 3-7. 168 231 Peacock International ... Per C. A. B 169 231 Big »» ... 170 230 Stanllyd Caerbryn . .. 171 231 Big Onlhvyn »> 172 231 , Abercraf „ 173 231 Eighteen Foot PwUfaron Percy, 96, p. 333 174 249 Black Glyn A.B.C. & C. (Ed. 1907), p. 124 175 230 Big Blaencaegurwen PerC.A.B 176 231 Four Foot Ystradgynlais... f* ... 177 228 Lower Level and BonviUe's Court Per C.A.B. and A.B.C. Kilgetty and Kilgetty & C.(Ed. 1907), p. 404 178 229 Big Carway A.B.C. & C. (Ed. 1907), p. 369 179 249 Brithdir ... Geol. Surv 180 232 Mynyddislwyn ... ,, 181 232 Tillery ... ,, 182 232 Red Ash 183 247 Five Foot (top) C.A.S 184 247 ,, (middle) „ 185 247 „ (bottom) „ 186 247 Four Foot (top) ... ,, 187 247 „ (bottom) 188 249 Black Celynen A.B.C. & C. (Ed. 1907), p. 127 189 249 Three Quarter Tirpentwys A.B.C. & C. (Ed. 1907), p. 132 190 229 Green Vein ... Cae Pontbren... A.B.C. & C. (Ed. 1907), p. 368 191 230 Peacock Garnant A.B.C. & C. (Ed. 1907). pp. 369 & 370 192 230 Stanllyd and Pumpquart Emlyn A.B.C. & C. (Ed. 1907), p. 371 193 247 Yankee Clyne Valley ... A.B.C. & C. (Ed. 1907), p. 382 194 247 Three Foot ... ,, A.B.C. & C. (Ed. 1907), p. 384 195 247 [Box Big] ... Glan Mwrwg ... A.B.C. & C. (Ed. 1907), p. 391 196 248 Forest Penrhiw A.B.C. & C. (Ed. 1907), p. 392 197 247 Lynch Lynch A.B.C. & C. (Ed. 1907), p. 394 198 228 Timber HiU Pit, Hook A.B.C. & C. (Ed. 1907), p. 405 ANALYSES. 25 No. on Plates 1 and 3-7. C. H. 0. N. C H ratio. Volatile Matter. Fuel- ratio. Sp. Gr. Ash. 168 93-73 3-22 3-05 29-12 . __ 1-8 169 95-15 93-20 2-11 3-12 2-74 45-07* 29-90 — — — 2-3 170 2-74 •94 -7 171 93-16 3-52 — — 26-43 5-48 17-26 — • 1-2 172 3-32 1-4 173 174 93-52 3-82 2-62 24-48 7-02 36-78 13-25 2-16 — 3-6 2-5 175 176 9313 91-81 95-68 93-72 89-73 87-66 87-87 88-33 92-55 2-17 3-99 3-04 3-68 5-71 6 09 6 01 5-79 4-88 4-70 4-20 42-97* 23 00 31-50 25-54 15-71 14-39 14-62 15-26 18-95 5-89 28-69 33-14 35-25 32-79 14-82 15-97 2-49 2-02 1-84 2-05 5-75 1-37 1-334 1-346 1-313 -7 1-7 177 -51 1 -77 1-0 178 2-60 1-6 179 180 181 182 2-88 1 1-68 4-38 1-87 4-67 ! 1-45 4-27 1 1-61 10-5 5-2 5-3 3-5 183 2-57 7-2 184 185 186 187 91-26 92-70 91-54 92-52 89-27 4-56 4-44 4-62 4-78 5-60 4-18 2-86 3-84 2-70 20-0 20-9 19-8 19-4 15-93 16-26 12-96 14-96 15-37 25-84 5-15 6-72 5-69 5-51 2-87 — 7-2 5-7 2-2 12-3 188 3-44 1-69 4-3 189 89-64 4-37 4-99 1-00 20-51 — — — 5-0 190 94-37 3-69 1-94 25-57 — — — 1-4 191 93-94 93-31 88-12 3-77 3-02 5-57 2-29 24-93 30-91 15-82 6-10 30-81 15-38 2-24 — 1-8 192 2-52 1 1-15 1-5 193 6-31 2-3 194 87-22 5-49 7-29 15-87 31-26 15-43 2-20 5-48 ~— 4-3 195 — — 4-4 196 86-38 5-37 6-97 1-28 16-07 — — — 1-8 197 94-72 3-25 — — 29-12 26-93 4-74 2-71 20-1 — 2-4 198 2-( )3 -8 * See footnote on p. 63. 26 THE COALS OF SOUTH WALES. No. on Plates 1-inch Local Name of 1 and map. Vein. Colliery. Authority. 3-7. 199 228 Bonville's Court C.A.S. ... 200 228 „ Reynalton A.B.C. & C. p. 404 (Ed! 1907)! 201 230 Little Vein ,.. Little VeinSlant, Ammanford A.B.C. & C. p. 367 (Ed. 1907). 202 248 Cae David Llynfi Percy, 76, p 332 203 247 Four Foot Clyne Valley ... A.B.C. & C. p. 383 (Ed. 1907), 204 249 Brithdir ... Geol. Surv. 205 J» Ras-laa 206 >t 207 11 Nine Foot 208 Tillery 209 11 Black ... 210 It »» 211 Nine Foot 212 »» >» 213 Mynyddislwyn 214 11 Brithdir ... 215 Big 216 11 Nine Foot 217 Mynyddislwyn 218 11 Black jj 219 248 Two-foot-nine Gov.'Lab. 220 ,, Lantern ... 221 >) No. 2 Rhondda ... " 222 Lantern 223 ty No. 3 Rhondda " 224 Rock fa wr 225 jj No. 2 Rhondda ,, 226 ^, Lower New ... 227 Victoria " 228 )) Wernddu or No. 2 Rhondda 229 J» Wernddu 230 No. 2 Rhondda " 231 j^ 11 ••• >> 232 „ Rock-fawT " 233 jj 11 ••• j» 234 j^ Forest-fach ... '* 235 Nine Foot " 236 >J No. 2 Rhondda *' 237 *' ... 238 ff Nine Foot or Ras Las >j 239 ,^ No. 3 Rhondda .•■ 240 „ ,, " ... ... 241 " Nine Foot, Red Coal )» 242 ,, No. 2 Rhondda 243 j^ No. 3 Rhondda " ... 244 „ Nine Foot " ... 245 Six Foot »> 246 No. 2 Rhondda " ANALYSES. at No. on c Plates 1 and C. H. 0. N. H Volatile Matter. Fuel- ratio. Sp. Gr. Ash. 3-7. ratio. 199 93-26 3-28 ' 3-46 28-43 _ , 200 — — - ■ — 6-89 15-99 — 11 201 94-36 3-63 2-01 26-02 — — — 1-5 202 90-78 5-13 4-09 17-69 24-74 3-04 5-4 203 88-80 90-08 5-36 5-21 5-84 16-55 17-27 30-30 28-15 2-31 2-55 1-373 2-6 204 3-08 1-63 10-2 205 91-85 4-57 2-02 1-66 20-11 18-78 4-32 1-385 6-1 206 91-77 4-52 2-18 1-53 20-31 17-77 4-63 1-342 3-9 207 90-86 4-88 2-79 1-47 18-60 25-62 2-90 1-348 4-76 208 86-23 6-53 6-54 1-66 16-59 38-42 1-60 1-333 4-3 209 86-62 5-10 6-72 1-66 16-98 36-52 1-74 1-379 8-1 210 88-08 5-15 5-25 1-62 17-09 34-57 1-89 1-331 6-06 211 91-73 4-29 2-36 1-62 21-39 16-53 5-05 1-367 4-3 212 89-79 6-03 3-83 1-35 17-86 27-76 2-60 1-377 8-4 213 88-30 6-29 4-60 1-81 16-70 30-60 2-77 1-318 3-8 214 89-23 6-27 3-92 1-58 16-94 30-10 2-32 1-344 5-8 215 87-17 6-16 6-29 1-38 16-90 35-06 1-86 1-345 61 216 90-36 4-86 3-26 1-53 18-60 23-64 3-23 1-328 41 217 86-61 6-54 6-98 1-87 15-63 37-56 1-66 1-311 3-3 218 88-41 5-21 4-79 1-59 16-97 32-82 2-06 1-330 5-6 219 90-86 4-59 2-99 1-56 19-80 20-97 3-77 1-306 5-02 220 85-02 6-32 8-02 1-64 16-00 39-62 1-53 1-289 14-64 221 85-37 6-18 7-86 1-59 16-48 38-00 1-63 1-311 5-25 222 84-50 6-26 8-63 1-61 16-00 37-22 1-67 1-299 4-98 223 87-17 5-54 5-67 1-62 15-75 37-00 1-70 1-281 6-92 224 85-15 5-05 813 1-67 16-86 38-07 1-63 1-296 3-26 225 87-83 511 5-39 1-67 17-20 3615 1-84 1-308 16-17 226 91-65 4-37 2-50 1-48 20-97 18-49 4-41 1-31S' 314 227 92-33 4-46 1-77 1-44 20-70 21-22 3-72 1-323 7-86 228 90-12 5-01 3-36 1-51 17-98 23-56 3-24 1-299 7-61 229 89-39 4-94 4-12 1-65 18-10 27-59 2-62 1-292 3-76 230 91-66 4-43 2-50 1-41 20-71 16-46 5-05 1-317 4-76 231 91-66 4-66 2-20 1-48 19-66 21-09 3-98 1-312 6-42 232 84-27 , 5-12 8-93 1-68 16-46 39-92 1-51 1-323 6-26 233 84-45 5-23 8-65 1-67 16-14 37-59 1-67 1-309 3-67 234 89-93 4-91 3-83 1-33 18-31 25-92 2-86 1-284 4-92 235 91-43 4-61 2-44 1-52 19-83 19-39 4-15 1-302 5-70 236 91-43 4-80 2-23 1-54 19-04 23-10 3-34 1-310 6-68 237 87-40 5-50 5-28 1-82 15-89 36-86 1-80 1-315 11-94 238 91-92 4-15 2-57 1-36 22-16 13-65 6-33 1-319 3-40 239 88-67 5-38 4-38 1-57 16-43 36-64 1-81 1-281 8-50 240 91-86 4-79 2-06 1-29 19-19 21-03 3-76 1-305 4-66 241 90-66 4-79 3 03 1-62 18-92 22-03 3-64 1-305 7-47 242 88-43 5-24 4-69 1-64 16-88 32-25 2-10 1-286 4-74 243 88-59 5-10 4-63 1-68 17-36 29-68 2-38 1-278 2-65 244 91 03 4-54 2-99 1-44 20-04 16-88 4-92 1-292 4-34 245 90-99 4-58 2-94 1-49 19-86 19-50 4-13 1-303 4-04 246 88-59 5-50 4-34 1-57 16-10 29-05 2-45 1-283 5-57 28 THE COALS OF SOUTH WALES. No. on Plates I and 1-inoh map. Local Name of Vein. Colliery. Authority. 3-7. 247 248 Red " _ - Gov. Lab 248 »» Six Foot ... ... ... 249 }> Nine Foot 250 »> Six Foot 251 }t Red 262 tt Six Foot ... 253 it >> ... ... ... 254 tf Nine Foot 255 H Four Foot ... 256 tr No. 2 Rhondda ... 257 » Nine Foot 258 »f »» ... ... ... ... 259 tt Four Foot ... ... 260 ft Six Foot \ 261 249 - Nine Foot ... 262 ft Six Foot 263 t9 Four Foot 264 248 Six Foot 265 231 Four Foot C.A.S 266 229 Green 267 229 Big ... ... 268 231 Brass ... 269 230 Middle 270 230 Red 271 230 Pumpquart . . . ... ... 272 231 Peacock ... 273 230 Stanllyd ... ... ... 274 232 Deep Black ... 275 230 ? 276 248 Werntarw 277 247 New 278 232 Deep Black (top) 279 »I „ (middle) ... ... ... 280 »» „ (bottom) ... ... 281 247 Four Foot 282 f» Five Foot ^,.. 283 230 Four Foot 284 tf Grolden 285 230, 231 No. 2 286 ? Big 287 ? ff • ■ • • . • 288 229 Yard ' 289 228 ? 290 231 Lower ' 291 231 Gnapiog 292 230 Stanllyd Big ... 293 230 Stanllyd ... 294 231 Blaenant ' 295 230 Two Foot Nine 296 230 Peacock 297 230 Big 298 230 Red * . ■ • ... ... 299 228 Rook ... ANALYSES. 29 Ko. on Plates 1 and C. H. 0. N. H Volatile Matter. Fuel- ratio. Sp. Qr. Ash. 3-7. ratio. 247 90'72 4-70 3-12 1-46 19-29 18-82 4-31 1-291 4-75 248 9013 4-44 3-96 1-47 20-30 16-86 4-94 1-319 5-61 249 91-13 4-49 2-86 1-52 20-30 16-32 5-13 1-316 4-60 250 91 -17 4-54 2-77 1-62 20-07 18-22 4-49 1-304 3-16 251 91-80 4-'31 2-54 1-35 21-29 14-37 6-92 1-277 6-54 252 91-32 4-28 ■ 3-01 1-39 21-34 15-27 5-56 1-328 5-40 253 91-33 4-23 3-01 1-43 21-59 15-37 6-51 1-337 5-17 254 91-64 4-34 2-47 1-65 21-09 14-01 6-14 1-305 4-07 255 91-79 4-31 2-60 1-30 21-29 14-41 5-94 1-303 5-97 256 89-32 6 09 3-74 1-85 17-54 27-21 2-64 1-287 6-94 257 91-42 -4-24 2-82 1-52 21-56 15-31 5-53 1-296 3-14 258 91-79 4-38 2-19 1-64 20-96 14-69 5-81 1-304 2-79 259 92-00 4-34 2-44 1-22 21-19 14-68 6-85 1-313 3-89 260 91-65 4-46 2-14 1-76 20-69 16-69 6-37 1-304 3-41 261 92-11 4-19 2-19 1-61 21-98 13-80 6-24 1-313 3-65 262 92-04 4-16 2-55 1-26 22-18 13-56 6-38 1-311 3-48 263 91-74 4-26 2-80 1-20 21-51 14-86 5-73 1-326 4-82 264 89-80 4-69 4-03 1-58 19-56 21-28 3-70 1-330 4-72 265 93-62 4-08 2-41 22-92 8-76 10-41 4-48 266 94-08 3-61 3-41 26-80 6-50 14-38 — 3-98 267 93-90 3-57 2-53 26-30 6-35 14-75 — , 1-70 268 93-88 3-73 2-39 25-17 6-45 14-50 — 1-64 269 93-78 3-62 2-60 25-90 6-74 16-42 1-66 270 93-99 3-67 2-34 25-61 6-83 13-64 _™ 4-54 271 94-81 3-46 1-74 27-48 7-94 19-24 — 2-94 272 93-90 3-68 2-42 27-58 6-25 16-00 1-66 273 94-00 3-56 2-44 26-40 5-81 16-06 — . 1-33 274 87-76 5-27 6-97 16-65 32-91 204 9-68 275 92-61 4-39 3-00 21-09 16-31 6-13 — 6-00 276 85-33 5-64 9-03 16-13 40-07 1-47 10-50 277 87-83 5-70 6-47- 15-41 38-18 1-62 — 8-90 278 85-95 5-46 8-59 15-74 36-59 1-73 — 11-52 279 85-49 5-63 8-88 15-18 37-88 1-64 — 8-38 280 86-62 6-60 7-78 15-40 36-08 1-77 — 11-60 281 91-54 4-34 4-12 21-09 15-64 6-39 — 6-10 282 90-82 4-28 4-90 21-22- 19-45 4-14 — 10-74 283 91-37 4-49 4-14 20-35 15-88 6-30 — 7-60 284 93-16 4-17 2-67 22-34 11-73 7-52 — 3-80 285 93-02 4-19 2-79 22-20 9-97 9-03 — 2-64 286 93-56 3-52 2-92 - 26-58 6-62 14-33 — 5-80 287 93-83 3-49 2-68 26-88 6-72 16-48 — — 288 94-17 3-78 2-06 24-91 7-34 12-62 — 1-24 289 94-88 3-38 1-74 28-07 5-68 16-92 — 318 290 94-52 3-61 1-97 26-93 6-15 15-26 — 2-90 291 93-93 3-66 2-42 25-74 6-30 14-87 - — 2-40 292 93-47 3-62 2-91 26-82 6-26 14-97 — 1-86 293 94-46 3-51 2-03 26-91 6-78 13-75 — 6-00 294 93-27 4-27 2-46 21-84 12-62 6-99 — 3-66 295 93-83 3-62 2-65 26-65 6-54 14-29 — ■ 2-78 296 94-44 3-42 2-14 27-61 5-75 16-39 — 1-86 297 94-29 3-42 2-29 27-67 6-85 16-09 — 2-00 298 93-92 3-70 2-38 26-38 6-79 13-73 — 2-00 299 95-09 3-28 1-63 28-99 4-76 20-05 2-20 c2r 30 THE COALS OF SOUTH WALES. No. on Plates 1 and 3-7. l-inch map. Local Name of Vein. Colliery. Authority. 300 301 302 303 304 303 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 230 230 230 230 230 230 231 231 228 231 230 230 230 248 230 ? 230 228 Rook (top) ... „ (middle) „ (bottom) Charcoal Three Foot One East Pit Big Three Foot Nine Foot Eighteen Foot StanUyd Lower Pump- quart. Triquart „ (top) ... ,, (middle) „ (lower) „ (bottom) Triquart Braslyd Red C.A.S. .. Notes. (1) No. 22. — The figures for Pure Coal as given in Percy are incorrect. The figures here given have been obtained by recalculating from " Compo- sition per cent., exclusive of water only." (2) No. 80 — ^The analysis here quoted is recalculated from the figures of " Gadly Four-Feet Seam," as given on p. 57 of the second Adm. Rept. under Analysis 1. Analysis 2 adds up to 100-97, thus giving no oxygen in the coal. (3) No. 85.— See Note (1). (4) No. 104.— The N, as given on p. 12 of Adm. Rept. 1, should read 1-02 (as on p. 59). The analysis adds up to 100-69, but a note on p. 58 states " The pure coal contained only 3-82 per cent, ash." There is obviously something wrong with the oxygen and ash, but this would not affect the C/H ratio, though rendering the' analysis as calculated to " Pure Coal " doubtful. (5) No. 113. — The figures given represent the mean of two different specimens. The greatest difference on "the Pure Coal was '01 in the C and •08 in the H. The percentage of ash in both specimens is, however, given. (6) No. 123. — The analyses as given on pp. 5 and 55 differ in O (9'76 and 9-96). In both cases the analyses add up to over 100 (102-00 and 102-20). As the O is obtained by difference, the figure should read 7-76. This Value, therefore, has been taken. (7) No. 128. — A similar case to No. 113 — see Note (5). CALORIFIC VALUES. 31 No. on H Plates 1 and C. H. 0. N. Volatile Matter. Fuel- ratio. Sp. Gr. Ash. 3-7. ratio. 300 93-99 3-62 2-39 25-96 6-80 13-70 3-14 301 94-88 3-64 1-48 26-07 7-26 12-79 8-92 302 93-54 3-67 2-79 25-49 7-38 12-55 — 9-40 303 94-24 3-28 2-48 28-73 5-45 17-35 — . 1-12 304 94-25 3-54 2-21 26-62 6-32 14-82 , 2-80 305 94-03 3-44 2-53 27-33 6-62 14-10 2-60 306 93-26 3-86 2-89 24-16 7-63 12-28 — 3-40 307 93-83 3-81 2-36 24-63 7-23 12-83 — , 3-20 308 93-67 3-81 2-52 24-68 7-25 12-79 — 1-20 309 94-36 3-03 2-61 31-14 8-69 10-64 __ 17-40 310 94-12 3-83 2-05 24-57 7-32 19-16 — 3-58 311 94-09 3-48 2-43 27-04 6-19 18-27 •80 312 94-31 3-35 2-34 28-16 6-09 18-64 1-00 313 94-16 3-45 2-39 27-30 5-46 17-31 3-04 314 91-99 4-32 3-69 21-29 15-21 .5-67 — 3-00 315 92-07 4-65 3-28 19-80 18-13 4-52 — , 7-80 316 92 03 4-40 3-57 20-91 14-68 5-81 2-40 317 92-38 4-35 3-27 20-93 14-48 5-91 — 4-40 318 94-41 3-36 2-23 28-10 5-80 16-24 — 6-92 319 93-32 3-65 3-02 25-57 6-96 13-37 — 3-30 320 93-22 3-85 2-92 24-21 8-78 10-43 2-80 321 94-30 3-29 2-40 28-66 5-50 17-81 — 2-82 Calorific Values. — These were determined in the Government Laboratory for the coak there analysed, namely, Nos. 219-264. Report by the GovernTnent Laboratory. The gross calorific value was determined on coal ground to pass through a 50-hole sieve, in a bomb-calorimeter (Mahler- Kroeker's type), suitable corrections being applied for radia- tion. The results of duplicate determinations were, as a rule, within 20 calories on about 8,000 calories per gram of coal. The net calorific value refers to the above-mentioned value after allowing for the condensation of steam. The calorific values calculated from the composition of the coal were obtained by the use of the following formulae for. the heat of combustion of carbon, hydrogen and sulphur : — (1) 8080 X C + 34460 (H— iO) + 2250 x S. (2) 8080 (0— 40) + 34460 x H -t- 2250 x S. These formulae are intended to allow to some extent for the different state of combination of the oxygen in tlie coal. Where both calculated values are appreciably less than the experi- mental values, this is probably to be accounted for by the presence of sulphur in the form of pyrites. 32 THE COALS OF SOTTISH WALES. Calculated Calories. No. on Determined Calorific Net Calorific Platea 1 Moisture. and 3-7. value Value. C+(H— JO) (0-|0) (gross). + s + H + S. 219 8,254 7,994 8,271 8,308 0-53 220 7,016 6,754 6,996 7,082 1-56 221 7,674 7,355 7,643 7,730 2-35 222 ' 7,726 7,424 7,663 7,762 2-00 223 7,916 7,598 7,944 8,014 116 224 7,931 7,623 7,750 _ 7,852 211 225 7,009 6,647 6,910 6,957 1-69 226 8,433 8,168 8,431 8,473 0-61 227 7,977 7,609 7,851 7,875 0-74 228 8,014 7,728 8,044 8,078 0-89 229 8,271 7,984 8,270 8,318 1-22 230 8,199 7,876 8,169 8,198 103 231 8,117 7,794 8,115 8,129 0-90 232 7,508 7,215 7,418 7,528 2-73 233 7,720 7,396 7,645 7,745 2-69 234 8,217 7,926 8,195 8,242 114 235 8,338 8,059 8,257 8,285 0-54 236 8,026 7,701 8,077 8,112 1-22 237 7,335 6,925 7,352 7,405 1-15 238 8,369 8,118 8,380 8,410 0-49 239 7.848 7,552 7,951 8,001 0-96 240 8,260 7,947 8,312 8,338 1-36 241 8,150 7,875 8,062 8,109 0-60 242 8,064 7,730 8,121 8,174 1-34 243 8,388 8,090 8,367 , 8,422 0-99 244 8,302 8,034 8,327 8,363 0-56 245 8,332 8,072 8,368 8,403 0-61 246 8,062 7,731 8,106 8,159 1-20 247 8,258 7,878 8,308 8,345 0-41 248 8,162 7,958 8,079 8,131 0-60 249 8,233 7,968 8,304 8,338 0-61 250 8,398 8,135 8,470 8,502' 0-50 251 8,209 7,954 8,198 8,231 0-59 252 8,202 7,956 8,147 8,195 0-82 253 8,253 8,018 8,193 8,224 0-55 254 8,324 8,072 8,346 8,373 0-71 255 8,111 7,847 8,121 8,157 0-90 256 8,043 7,749 8,086 8,127 1-20 257 8,395 8,145 8,360 8,393 0-62 258 8,492 8,232 8,487 8,512 0-67 259 8,413 8,160 8,402 8,430 0-50 260 8,484 8,232 8,468 8,492 0-63 261 8,415 8,165 8,382 8,407 0-69 262 8,423 8,177 8,364 8,394 0-67 263 8,238 7,992 8,247 8,280 0-74 264 8,197 7,942 8,169 8,218 0-70 Calories per gram. 3ti CHAPTEE IV. AccuKACY OF Coal Analyses. By W. POLLAED. Although practically every author on the subject of coals and coal-analysis has discussed, or at any rate alluded to the ques- tion of errors in coal-analysis, it will probably be of assistance if a few examples of possible errors are given before examining the table of analyses. These examples may be thought to be exaggerated, but probably all, and possibly some others not mentioned, will be met with sooner or later whenever a large amount of coal-analysis is done. 1. — Peoximate Analysis. In the proximate analysis of a coal it is important to work as much as possible under constant conditions, and so long as this is done duplicate estimations agree fairly well. If, however, the strength of flame, time of heating, size of crucible, &c., be altered, the results will almost invariably differ, and, unless these details are looked after, will be unreliable. Muck* points out that the addition of powdered quartz to a coal increases the coke, and consequently lowers the volatile matter, so that if two coals are being dealt with whose composition is identical as regards combustible constituents, but which differ in the amount of ash, the proximate analysis will be to some extent misleading. From some experiments carried out in this laboratory it was found that an increase of water gave an increase in the volatile matter. The following figures illustrate this point. In the first column is the analysis of the original coal, in the second the coal plus an addition of 5 per cent, water,' in the third with an addition of 12 per cent, water. The results are calculated on the pure coal (i.e., less moisture and ash) : — Volatile matter 37-02 ... 37-86 ... 38-44 Fixed carbonaceous residue 62-98 ... 62-14 ... 61-56 * " Chemie d. Steinkohlen," Bonn, 1876, p. 16. 34 THE COALS OF SOUTH WALES. The presence in the coal of carbonates also affects the results. In a coal which contained 12 per cent, carbonic acid (present in the coal as carbonate of lime and magnesia), analysed in the Geological Survey Laboratory, the amount of carbonic acid left in the coke after the estimation of volatile matter was only •9 per cent., hence 114 per cent, had gone off as volatile matter. Further, it is not possible to say to what extent the reaction COj + C= 200 goes on, but this must have a considerable effect on the result. Pyrites in the coal must also have some effect, but it is not easy to judge to what extent. It will be readily seen from the above remarks that the proximate analysis is not sufficiently reliable as a basis for purposes of classification. ' 2. — Ultimate Analysis. The report of Sub-Committee X of the International Com- mittee on Analyses of the Eighth International Congress of Applied Chemistry (1912) requires careful consideration, as errors in the estimation of moisture naturally affect practically all constituents, though especially the hydrogen and conse- quently the 0/H ratio. The following is an outline of the work done by the Sub-Committee. Samples of six different coals were submitted to the members of the Sub-Committee who were asked to estimate the moisture by various methods, and to submit their results with any recom- mendations they thought advisable. The coal-samples were packed ready ground in tins so that each worker should have as far as is possible a true sample. The coals consisted of — 1. A Welsh anthracite. 2. "Ten Yard" or ;' Thick Coal" of South Stafford- shire (rather like a lignite). 3. " Kilburn " Seam of Leicestershire. A coking and household coal. 4. A South American coal. This coal rapidly weathers and contains 37 per cent, of ash. It is of excep- tional character and unlike any coal known to us in South Wales. Its consideration might be omitted. 5. A bituminous coal from Leicestershire. 6. A coal from the south-east of Scotland, bituminous, but less so than No. 5. The /ollowing table gives the main results : — ACOTJHACY OF ANALYSES. 35 >o 1— i SziO «o o «0 1— t O lO o « IN O ^-t a to IN IN ^ - t- ffl » I— t '-' ^ o ^SS (M ^ -3 o toioio pH O M !^ sss? S 00 !D t- 1— 1 o ja IN (3 in oorti t- o ^ (NtHOO t;- >:> 0)09 •a 13 l-l d 6 o r- © ^ i fH s ;^ S!?2^ g o M N N cd -s (5 s .a ; ; ; ; T3 . . • ' ij, *IH O ; ; ; ; « e r. & ig S 1 1 • Maximum Minimum, Average 1 m (N r^ l> 50 t- 1— 1 (£> © 00 o S»5 i-H OS © © r^ ■* 00 iffl © IN O l> r-l © lO lO 1— 1 N O 00 (N © lOO r^ t- «5 t- IN l> © ■^ 1— 1 INt-© U5 O 00 03 rH 00 tH t> ■* r-( in 00 © MINS 00 OS o •* 00 t- t- t- S OS (N IN t- © I> OS l> »H IN ,-llN t- OS © u5 m i-H ^ i> © so -H ^ t- to t~ F-H •4-> •1 a o j= -i rr © o © © rt M t- o ©OS OS Fh »— t s ^ o n .4 fti ©U5 OS ^ 1-1 t" 05 ■^ ^' CO IN N TS l>, n P4 : : : o l>> : i : 8 f^ Tl . . . £ ^ !§ Na fi 40 SS-^ d d ;z! in pH F-l t^ O ■* 00© ■* in 00 © t- ^ 0> 00 t- 1—1 t- OS (N 00 t-«3 O IN •<* in 00 eq 00 CO CO ©com IN »eo o in OS OS ■* o t- in i> 00 «0 OS CO © OS OS '1— 1 I-H' o 1-1 in OS t> -^os (N COIN cq fH S : : : : a > S c3 .s . . . 1 \ • • • ttt ■^ d f Maximum Minimum Average a 1 1 O ^ 36 THE COALS OF SOUTH WALES. a, la a g s ^ ^o •*eq >o (M so + a> t;- op (N d i> t^ t^ IN so l?5 so rH r-^ S 1 (M O 05 IN o 1 r-H lO to so CO 1^- t^ 00 l> t^ l> n OT 5 n

I-H (N to 50 SO ■* + «p«-f lO M + -^ op q> M d 00 l> t^ 00 O 'A p-f fH "3 1 M O t- M o O 1 P rH >0 P CO l> t^ N O O (N 1, + tO(N-* ■* 6 6 6 i-H rH rH SO 00 rH CSl iH 1 rl SO (M K> 1 Sp-f-H T* ^ 1 6 6 6 1— 1 l-H r-^ lO (N rH « rH + rH SO m "? d P5 !N N « 1> |Zi cop 1— ( c8 6 1 qjio op ^ iH t^- o « so eo 00 00 ? ! ss s I o c- 05 m ^ so so 5; §^ CO so so 2S rH 00 00 00 IN ^ i> t' 00 00 so M g OO iH I-H ? S j 88-24 90-74 90-45 5-24 4-84 5-28 6-52 4-42 4-27 16-8 18-7 17-1 1-91 Maximum difference ... 2-50* -44 2-25* 1-9 — Black [or Ras-las] 87-49 89-27 5-33 5-60 7^8 5-13 16-4, 15-9 1-74 2^87 DifEei;ence 1-78 -27 2-05 -5 113 Big [probably aboVe the Ras- las] 93-77 93-63 93-99 93-87 3-74 3-70 3-76 3-76 2-49 2-67 2-25 2-37 25-1 25-3 25-0 25-0 14-46 13-87 Maximum difference ... -36 -06 •42 -3 ■59 Big [or Ras-las] 71 J) 93-56 93-21 92-46 3-57 3-57 ■3-20 2-87 3-22 4-34 26-2 26-1 28-9 15-95 10-76 Maximum difierence ... 1-10 •37 1-47 2-8 5-19 * Greatest difference observed in this Table. 48 THE COALS OF SOUTH WALJBS. Vein. 0% H% 0&N0/„ C/H Fuel- ratio. Four Foot [of Clyne Valley].. 88-80 88-51 6-36 5-02 5-84 6-47 16-6 17-6 231 2 •56 Difference -29 -34 -63 1-0 .•25 Big [or Ras-las] It »» 93-87 93-97 94-49 3-59 3-50 3-67 2-54 2-53 1-84 26-2 26-9 25-8 22^8 16-2 Maximum difference •62 -17 •70 1-1 6-6 Big [orEas-las] 93-91 93-16 3-70 3-52 2-39 3-32 25-4 26-4 15-4 Difference -75 -18 -93 1-0 — Little [or Braas] 94-19 94-36 3-58 3-63 2-23 2-01 26-3 26-0 18-5 Difference -17 -05 -22 -3 — Peacock [or Brass] 93-39 93-80 3-66 3-16 2-95 3-04 25-5 29 ^6 18-0 Difference -41 -50 -09 4.x* — Rock Vatrr [No. 2 Rhondda] 85-23 84-78 4^80 5^57 9^97 9^65 17-8 15-2 1-46 1-31 Difference •45 •77* •32 2-6 •15 No. a Rhondda 91-78 91-66 91-66 5^13 4^85 4 43 319 3^49 391 17-9 18-9 20-7 4-47 4^12 505 Difference •12 •70 •72 2-8 •93 Three Quarter [of Monmouthshire] »» f> ••• 87^81 89^64 5 •OS 4^37 7^10 5 99 173 20-5 2 09 Difference 1-83 •72 Ml 3-2 — Graigola »» •■• ••• ••• 92-73 91-70 4^64 4^80 2-63 3^50 20^0 19-1 5 •a? Difference 1^03 •16 ■87 •9 — * Greatest difference observed in this Table. DIFFERENT SAMPLES FROM THE SAME SEAM. 4! Vein. c% H% 0&N% C/H ratio. Fuel- ratio. Tregloin 93-79 93-78 3-67 3-59 2-54 2-63 25-6 26-1 17^8 17-1 DifEerence -01 -08 •09 •5 •7 Red [of the Neath VaUey] ... 93 26 92-74 92-48 3-89 3-96 4-03 2-85 3 30 3 49 240 23^4 23 12-6 12-9 15-6 Maximum difference ... -78 •14 •64 1-0 3-0 Red [of the Neath VaUey] Difference 93-56 93-42 3-48 3-39 2-96 3-19 26-9 27-5 •14 -09 -23 -6 10-1 Red [of the Neath Valley] ... 93-32 ... 94-08 3-84 3-79 2-84 2-13 24-3 24-9 14-6 14-4 Difference -76 -05 -71 -6 -2 Red [of the Neath VaUey] ... »» f> '•• 93^02 92^58 4^27 3-91 2-71 3 50 21^8 23^7 12-7 120 Difference •44 •36 •79 1-9 •7 Big »» ... 93^72 93-90 3-68 3-57 £•60 2^53 25^5 263 15-97 14-75 Difference -18 •11 •07 •8 1-22 StanUyd 94-06 94-09 3-47 3-48 2-47 2-43 27-1 27-0 16-52 18-27 Difference -03 -01 -04 -1 1-75 Red 93-42 93-22 4-02 3-85 2-56 2-92 23-2 24-2 14-38 10-43 Difference •20 -17 •36 1-0 3-95 Nine foot 93^83 93-67 3-81 3-81 2 36 2^52 24-6 24-6 12-83 12-79 Difference -16 — -16 — •04 50 THE COALS OF SOUfH WALES. Vein. 0% H% 0&N% C/H ratio. Fuel- ratio. Nine Toot 91-40 91-43 -03 4-78 4-61 3-82 3-96 19-1 19-8 4-69 4-15 Difference -17 -14 •7 -54 Nine foot 91-73 9211 4-29 4-19 3-98 3-70 21-4 22^0 5 05 6-24 Difference •38 -10. ■28 •6 1-19 Peacock Brass 93-70 93-88 3-90 3-73 2-40 2-39 24^0 25-2 14-76 14-50 Difference -18 •17 •01 1-2 -26 The greatest differences observed in tlie two cases are there- fore : — (1) Different parts of the same vein : — c% H% 0&N% 0/H ratio Maximum difference 2-27 -44 2-34 2-0 Mean of max. differences 1-4 •19 1-49 -8 (2) In same vein and pit but different samples and some- times different analysts : — 7o H7o 0&N7„ C/H ratio Maximum difference 2-SO 77 2-26 41 Mean of max. differences •64 "24 ■67 1-2 From the above data it will be seen that it is impossible to lay down on a map the composition of the coals with minute accuracy, and that the exact limits of anthracite, steam-,, and house-coals is still indefinite, from a chemical point of view. It is quite possible that some of the early analyses may be inaccurate, for when charcoal-furnaces only were available for making combustions, the labour and difficulties must have been great. It should also be borne in mind that, in many cases, no details as to the collection of the samples are available, so that it is possible that the analyses in some cases represent a part of the vein only, and not the average composition of the whole thickness. CHAPTER VI. COMPAMSON OF DIFFERENT SeAMS IN THE SaMB LOCALITY. By W. Pollard. It is frequently the case that the lower the vein, in geological sequence, the more anthracitic it is. This rule, if proved to be universally correct, would be a point in favour of anthracitisa- tion having been due to a cause operating from beneath. Also it should be possible, if the composition of the upper veins were known, to predict what the approximate composition of the lower veins would be. To test these points the following table of analyses of different veins from the same pits has been pre- pared, giving the approximate distance between veins, com- position of the pure coal, C/H ratio, and fuel-ratio. Distance Vein. between c% H% O&N C/H* Fuel-t veins in % ratio. ratio. yards. Charcoal 174 84-56 6-57 8-87 12-9 2-10 Black 87 49 5-33 7-18 16-4 1-74 89-27 5-60 5-13 15-9 2-87 Four Foot 47 93-69 .3-74 2-57 25-1 13-9 Big 9316 3-52 3-32 26-4 — 93-91 3-70 2-39 25-4 15-4 21 Peacock 94-02 3-96 2-30 23-7 12-9 Four Foot 93-77 4-64 1-59 20-2 7-92 „ DyfEryn ... 54 td 70 92-93 4-91 2-16 18-9 5-16 Nine Foot 91-89 4-59 3-54 20-0 6-03 Red 17 87-77 4-97 7-26 17-7 2-22 Three Quarter ... 20 86-63 5-13 8-24 16-9 1-95 Rock 88-30 5-45 6-25 16-2 1-77 88-61 5-29 6-10 16-8 2-03 Deep Black 50 87-76 5-27 6-97 16-7 2-04 Old 87-93 5-30 6-77 16-6 2-18 No. 2 Rhondda 75 to 80 92-64 4-74 2-62 19-5 4-77 Graig 161 to 210 92-57 4-72 2-71 19-6 5-12 Two Foot Nine... 12 to 22 94-11 4-19 1-70 22-5 8-06 Four Foot 92-74 3-96 3-30 23-4 8-75 * The relative proportion of carbon to hydrogen. See Chap. VII. t The relative proportion of coke to volatile matter. See Chap. VII. 52, THE COALS. OF SOUTH AVALES. • Distance Vein. between 0% H% O&N C/H Fuel- Veins in % ratio. ratio. yards. Big or Stanllyd 94-21 3-75 2-04 25-1 16-4 93-82 3-81 2-37 24-6 16-2 93-13 2-17 4.70 43-0* — 35 Peacock 48 93-67 3-73 2-60 25-1 161 Middle ... 17 94-31 3-64 2-05 25-9 18-1 Lower 94-09 3-58 2-33 26-3 18-5 EUed 5 to 11 84-42 5-48 10-10 15-4 — Big 8 to 12 87-14 6-49 6-37 13-4 — (Top of) Three 89-81 5-11 5-08 17-6 2-99 Quarter • Three Quarter ... 83 to 99 86-25 5-90 7-85 14-6 Old 90-74 5-23 4-03 17-4 3-40 No. 2 Rhondda 70 93-58 4-05 2-37 23-1 12-1 Lower 93-71 3-69 2-60 25-4 12-4 Four Foot 88-51 5-02 6-47 17-6 2-56 88-80 5-36 5-84 16-6 2-30 12 Yankee 10 88-12 5-57 6-31 15-8 2-24 Yard 87-22 5-49 7-29 15-9 2-20 Upper Four Foot 64 to 71 90-92 4-51 4-57 20-2 — Ras-las 90-87 4-65 4-48 19-5 — Graig 151 to 210 91-66 4-71 3-63 19-5 410 Two Foot Nine,.. 12 to 22 93-35 4-15 2-50 22-5 7-96 Four Foot 23 to 35 91-86 3-93 4-21 23-4 8-42 Six Foot 92-73 3-95. 3-32 23-5 7-31 Big 35 9317 2-12 4-71 43-9* — Peacock 93-94 3-77 2-29 24-9 15-4 * See Note on p. 63. DirFEEENT SEAMS IN THE SAME LOCALITY. 53 Distance Vein. between c% H% O&N C/H Fuel- veins in % ratio. ratio. yards. Six Foot « 49 93-63 4-01 2-36 23-4 — Nine Foot 92-65 3-96 3-39 23-4 10-7 Red 332 93-03 3-51 3-46 26-6 11-9 Big 93-92 3-55 2-53 26-5 19-0 94-49 3-67 1-84 25-8 20 to 35 Brass 93-39 3-66 2-96 25-5 18-0 93-80 3-16 3-04 29-6 Big 6 to 14 87-81 5-12 7-07 17-2 2-03 Tiiree Quarter ... 54 to 59 87-20 5-10 7-70 17-1 2-05 Meadow 87-16 5-42 7-42 16-1 1-95 Yard 39 90-53 4-98 4-49 18-2 t 3-32 Cae David 87-99 5-64 6-37 15-6 1-91 90-78 5-13 4-09 17-7 3-04 146 DufErjn:! 20 89-75 4-92 5-33 18-2 3-29 Lower Six Foot 38 to 43 91-25 4-84 3-91 18-9 3-96 Nine Foot 91-37 4-93 3-70 18-5 3-99 Four Foot 73 85-20 5-40 9-40 16-8 2-27 Nine Foot 59 86-30 5-34 8-36 16-2 2-29 Cribbwr 87-50 5-15 7-35 17-0 2-46 Penyfilia or Five 91-66 4-87 3-47 18-8 4-32 Foot. 88-66 6-03 5-31 14-7 2-84 141 Six Foot 13 90-75 4-73 4-52 19-2 3-93 Three Foot 91-46 6-02 3-49 18-2 4-08 Forest 5 to 8 86-38 5-37 8-25 161 — No. 3 Rhondda 88-44 5-32 6-24 16-6 2-94 Wemffraith ... 199 to 256 92-45 4-80 2-75 19-3 — Graigola 92-73 4-64 2-63 20-0 — 91-70 4-80 3-50 19-1 6-37 54 THE COALS OF SOUTH WALES. Distance Vein. between veins in yards. c% H% O&N % C/H ratio. Fuel- ratio. Red 333. 92-48 4-03 , 3-49 23-0 15-6 Big 93-96 3-74 2-30 25-1 17-2 Eighteen Foot . . . 9 to 16 93-52 3-82 2-62 24-5 13-3 Cornish 30 to 35 93-83 3-95 2-22 23-8 13-8 Nine Foot 93-79 3-86 2-35 24-3 15-0 Tillery 232 86-28 5-53 8-19 15-6 1-60 Big 5 90-58 5-39 4-03 16-8 — Three Quarter ... 87-81 5-09 7-10 17-2 2-09 89-64 4-37 5-99 20-5 — . 30 Black 88-24 5-24 6-52 16-8 1-91 t 90-74 4-84 4-42 18-7 Lower Trichwart about 17 94-1 3-6 2-3 26-1 18-6 Lower Pumpquart 93-00 3-68 3-32 25-3 18-3 Drap 83 92-59 4-54 2-87 20-4 — Green 26 93-98 3-88 2-14 24-2 13-9 Big 93.83 3-74 2-43 25-1 13-9 93-77 3-74 2-49 25-1 14-5 Slatog 36 to 38 83-63 5-28 11-09 15-8 1-80 Curly 14 to 17 85-93 5-92 8-15 14-5 1-65 Bodwr 17 to 18 85-69 5-81 8-50 14-7 _ 1-97 Hughes 77-40 4-67 ' 17-93 16'6 •94 Big 21 95-15 2-11 1 2-74 45-1* Peacock 93-73 3-22 3-05 1 1 29-1 Ward's Fiery ... 220 94-68 4-23 1-09 22-4 Graigola 90-14 5-03 1 4-83 17-9 3-82 * See Note on p. 63 DIFFERENT SEAMS IN THE SAME LOCALITY. 55 Distance Vein. between c% H% O&N C/H Fuel- veins in % ratio. ratio. yards. Four Foot 120 920S 4-70 3-27 19-6 6-60 Five Foot 92-17 4-63 3-20 20-0 5-87 Four Foot 44 91-8^ 3-99 4-20 23-0 Big 93-88 3-65 2-47 25-7 Stanllyd ' 94-06 3-47 2-47 27-1 16-5 »» 93-31 3-02 3-67 30-9 — if 94-09 3-48 2-43 27-0 18-3 114 Trichwart 46 94-16 3-45 2-39 27-3 17-3 Lower Pumpquart 94-31 3-35 2-34 28-2 18-6 Red 290 93-99 3-67 2-34 25-6 13-6 Little 94-19 3-58 2-23 26-3 18-5 94-36 3-63 2-01 26-0 — Red 333 93-92 3-70 2-38 25-4 13-7 Big 20 94-29 3-42 2-29 27-6 16-1 Peacock 19 94-44 3-42 2-14 27-6 16-4 Tregloin 93-79 3-63 2-58 25-8 17-5 Four Foot 260 91-37 4-49 4-14 20-4 5-3 Golden 93-16 4-17 2-67 22-3 7-5 StanUyd 20 93-47 3-62 2-91 25-8 150 Peacock 93-92 3-57 2-51 26-3 — Four Foot 116 91-54 4-34 4-12 21-1 5-4 Five Foot 90-82 4-28 4-90 21-2 4-1 Big 20 93-37 3-43 3-20 27-2 17-5 Brass 93-88 3-73 2-39 25-2 14-5 Peacock 65 93-70 3-90 2-40 24-0 14-8 Lower 94-52 3-51 1-97 26-9 15-3 56 THE COALS OF SOUTH WALES. Distance between c% H% O&N C/H Fuel- Vein. Veins in % ratio. ratio. yards. i Nine Foot 93-83 3-81 2-36 24-6 12-8 „ 20 93-67 3-81 2-62 24-6 12-8 Peacock 93-90 3-68 2-42 27-6 15-0 No. 3 Rhondda 350 91-86 * 4-79 3-35 19-2 3-8 Nine Foot 91-92 4-15 3-93 22-2 6-3 Six Foot 6 91-32 4-28 4-40 21-3 5-6 Red , 91-80 4-31 3-89 21-3 5-9 Four Foot 24 91-79 4-31 3-90 21-3 5-9 Six Foot 31 91-33 4-23 4-44 21-6 5-5 Nine Foot 91-64 4-34 4-02 21-1 6-1 Four Foot 19 92-00 4-34 3-66 21-2 5-8 Six Foot 39 91-65 4-45 3-90 20-6 5-2 Nine Foot 91-58 4-51 3-91 20-3 4-6 Six Foot 45 90-13 4-44 5-43 20-3 . 4-9 Nine Foot 91-13 4-49 4-38 20-3 5-1 Six Foot 45 90-99 4-58 4-43 19-9 4-1 Nine Foot 91-03 4-54 4-43 20-0 5-0 Ff crest Fach ... 347 89-93 4-91 5-16 18-3 2-9 Nine Foot 91-40 4-78 3-82 19-1 4-7 ,, ... 91-43 4-61 3-96 19-8 4-2 No. 2 Rhondda 80 87-40 5-50 7-10 15-9 1-8 No. 3 Rhondda 88-67 5-38 5-95 16-4 1-8 Four Foot 26 91-74 4-26 4-00 21-6 5-7 Six Fpot 25 92-04 4-15 3-81 22-2 6-4 Nine Foot 91-73 4-29 3-98 21.4 5-1 t> ••■ 92-11 4-19 3-70 22-0 6-2 DIFFERENT SEAMS IN THE SAME LOCALITY. 57 Vein. Distance between Veins in yards. c% H% O&N % C/H ratio. Fuel- ratio. Lower Pumpquart Charcoal about 35 93-87 94-24 3-41 3-28 2-72 2-48 27-5 28-7 • 25-1 17-4 On going through this Table it will be seen that approxi- mately in about half the cases the lower the vein the higher the carbon. Of the remainder several show the reverse, while in others the carbon varies irregularly. The same result approxi- mately is obs.erved in the carbon-hydrogen ratio. The general truth, however, of the rule that in any one locality the lower seams are more anthracitic tTian those above them is shown by the charts. A comparison of Plates 4 and 5, 5 and 6, or 6 and 7 shows that the lower seams become anthra- citic in parts of the coalfield where the higher seams retain their bituminous character. 58 CHAPTER VII. Classification of Coals. By W. POLLAED. The more recent gapers on this subject are: — C. A. Seyler, ' Chemical Classification of Coal,' Proc. S. Wales Irvst. Eng., Vol. XXI, p. 483, and Vol. XXII, p. 112. ' Report on the Operation of the Coal Testing Plant of the U.S. Geol. Survey,' Professional Papers, No. 48, Part I., p. 156. S. W. Parr, ' The Classification of Coals,' /. Am. Chem. Soc, Vol. XXVIII, 1906, p. 1425, and Colliery Guardian, Vol. XCIl, 1906, p. 1209.. F. F. Grout, 'The Composition of Coals,' Econonnic Geology, Vol. II, 1907, p. 225. D. B. Bowling. Report No. 1035 of the Geol. Survey Branch of the Department of Mines, Canada, p. 43. D. White. Bui. 382, U.S. Geol. Survey, p. 8. The Pennsylvania System (Fuel Ratio) will be found in Report M.M. of the second geological survey of Pennsylvania. In Mr. Seyler's paper, on pp. 483-491, a good resume of the older classifications is given. "His own classification, though not perfect, is one of the best, if not the best, so far available. It is based on the percentage of hydrogen and carbon, calculated on the pure coal. The hydrogen determines the genus and the carbon the species. The following table, taken from ' Analyses of British Coals and Coke ' (p. xv), gives the system : — r)9 60 THE COALS OF SOUTH WALES. The United States Geological Survey have recently dealt with methods of classification of coals, but do not mention Mr. Seyler's paper. The classification finally adopted by them is founded on the proportion of carbon to hydrogen, and the limits proposed for the different classes of coal are as follows* : — C/H ratio. A B C D E r G H I J K L Graphite Anthracite ... Semi-anthracite Semi-bituminous Bituminous Lignite Peat Wood (cellulose) 00 to! ? to ?30 ?30 to ?26 ?26 to ?23 ?23 to 20 20 to 17 • 17 to 14-4 144 to 12-5 12-5 to 11-2 11-2 to ?9-3 ?9-3 to ? 7-2 The classification founded on the fuel-ratio, that is, on the relation of coke to volatile matter on coal free from water and ash, as adopted by the Pennsylvania Geological Survey, may be summarised as follows : — Fuel-ratio. Anthracite ... Semi-anthracite Semi-bituminous Bituminous ... 12 and over. 8 to 12 5 to 8 to 5 This system has been found to be unsatisfactory, except for the anthracitic and semi-anthracitic coals. Prof. Parr has recently proposed a classification, based on the factor VC x -q-, where VC represents the volatile carbon unassociated with hydrogen, and C the total carbon in the coal. In the bituminous and lignitious classes "inert volatile" (volatile matter less volatile carbon) is made use of for the * This system has also been discussed by B. Renault, ' Sur quelques Micro - organismes des Combustibles fossiles.' Bulletin de la Soc. de Vlndusirie Minerale. S6r. 3, t. xiii, 1899, and t. xiv, 1900. Also separately published. CLASSIFICATION OF COALS. 61 purpose of further discrimination. In the following^ table the proposed limits are given : — VC X 100 Inert Volatile. Anthracite Semi-anthracite Semi-bituminous Bituminous A .. B.. C .. D.. Black Lignite .. Brown Lignite 4 and under 4 to 8 10 to 15 20 to 32 20 to 27 32 to 44 27 to 44 27 and oVer 27 and over 5 to 10 10 to 15 5 to 10 10 to 15 16 to 20 20 to 30 A further suggestion is made to express " Intrinsic Value " or "Relative Merit " of coals as fuel, assuming the true fuel- value of the coal to depend on the total carbon, available hydrogen and sulphur. The method is best shown by an example, for a coal composed of — 78-31 per cent. 4-31 „ •90 „ 83-52 or 120. This means Carbon ... Hydrogen Sulphur 100 -8352 Hence the " Gross Coal Index " is that with this coal 120 lbs. will be required to make 100 lbs. of actual fuel. Apparently the most recent classification is that of Professor Grout. It may be briefly stated to be based on fixed carbon for the anthracites to semi-bituminous, and on fixed carbon and total carbon for the bituminous and lignitious coals. Apart from a suggested diagrammatic representation of coals, the following table shows the classification proposed. All data are calculated on coal free from ash and water : — ITixed Carbon. Total Carbon. Graphite over 99 Anthracite over 93 — Semi-anthracite 83 to 93 — Semi-bituminous ... 73 to 83 — High grade bituminous . 48 to 73 82 to 88 Low grade bituminous 48 to 73 76-2 to 82 Cannel 36 to 48 76-2 to 88 Black Lignite 35 to 60 73-6 to 76-2 Brown lignite 30 to 55 65 to 73-6 Peat and Turf below 55 below 65 Wood ~~— — — , Dowling suggests the ratio of fixed carbon plus one half the e2 62 THE COALS or SOUTH WALES. volatile matter, divided by moisture plus oiie half the volatile matter, the analyses being made on the air-dry sample. White's ratio is carbon divided by oxygen plus ash. The data on which the various classifications here mentioned are based are therefore : — (1) Percentage of carbon and hydrogen, calculated on pure coal. (2) The relative proportion of carbon to hydrogen — that is, the C/H ratio. (3) The relative proportion of coke to volatile matter — that is, the fuel- ratio. (4) Volatile carbon X ; ; — with due consideration of " inert ; ,., „ total carbon volatile. ~ (6) Fixed carbon with due consideration of total carbon in pure coal. Fixed carbon + ^ volatile matter . Moisture + J Volatile matter. *''' 0+ash. Before comparing the value of these classifications for the present purpose it should be stated that the following remarks apply only from the anthracite to the bituminous or per-bitu- minous coals, as lignites do not occur in this coalfield, although in one or two cases coals nearing the lignitious class have been met with. Oxygen is obtained by difference, and the occasional inac- curacies in estimation of ash have been alluded to. The volatile matter and fixed carbon estimations have also been shown to be liable to considerable errors, so none of these figures should be taken for purposes of classification if better are available. Mr. Seyler has shown also that the hydrogen and volatile matter are closely connected, so that any system in which volatile matter, and hence coke, are made use of, together with total carbon, practically amounts to classifying on carbon and hydrogen. And as carbon and hydrogen can be estimated with great accuracy, it seems more rational to use them as a basis in classification, although the proximate analysis of a coal is, in most cases, sufficient to discriminate between anthracite, semi-anthracite, and semi-bituminous coals. The choice of classification for the present purpose therefore lies between Mr. Seyler's and the carbon-hydrogen ratio. As the object in view is to show the progressive change in character of the coal in this coal-field, and as this is most obviously shown by figures on a map, the preference falls to the C/H ratio. This ratio has the disadvantage that there is necessarily a certain amount of overlapping in the various groups and species, but it has the advantage of combining those two constituents which can be simultaneously and directly estimated with a con- siderable degree of accuracy, and of avoiding the necessity of recalculating on to the pure coal, when, as has been shown, considerable errors may be introduced through the oxygen having to be taken as the difference of the sum of all other constituents and 100. The only serious causes of error likely to occur in the C/H ratio are inaccuracies of moisture-deter- minates and the presence of carbonates or hydrous minerals in CLASSIFICATION OF COALS. 63 the coal, two of which would probably be observed and the carbonate, at any rate, corrected for. The C/H limits as pro- posed by the United States Geological Survey would require to be modified for this coal-field, as there are, for example, many good anthracites with a C/H ratio of less than 26. The limits as marked on the maps do not designate a hard and fast line, and are not intended to imply, for instance, that all coals on one side of, say, a line marked 23 are anthracites, whilst all those on the other are semi-anthracites, &c., but are only intended to illustrate the general distribution of the different classes of coal. In the following table the C/H limits theoretically possible for the various coals of Mr. Seyler's classification are given, also the limits observed for the various analyses here published, arranged on the same classification. In the Tables of analyses in this Memoir all available ultimate analyses have been made use of, provided locality and vein could be identified, as it appeared fairer to do this than to select analyses. In a few cases where an ultimate analysis was not available the proximate has been given. Where there appears reason to think an analysis is doubtful or does not represent a fair sample of the vein, attention is drawn to the fact in a footnote. Anihracitic Genus. Species. Possible limits of C/H ratio. Observed limits. No. of cases. Ortho-anthracite Sub-carbonaceous ... Sub-metabituminous Pseudo- I Sub-orthobituminous Anthracite Sub-parabituminous Sub-metaUgnitious ^ Sub-ortholignitious 23-3 and oVer 22 '8 and over 22-25 and over 21-75 and over 21 '0 and over 20-0 and over 18-75 and o\er 23-7 and over 23 to 29-9* None observed 22 '08 None observed 91 19 Carbonaceous Genus. Semi-anthracitio 20-7—24 ? 21-3 to 23-35 10 Ortho-carbonaceous 20-3— 23-3 20-6 to 23 '0 36 Sub-metabituminous 19-7— 22-8 20-3 to 21-2 6 Sub-orthobituminous 19-3— 22-2 20-31 1 Sub-parabituminous 18-7— 21-75 1 Sub-metalignitious 21-0— 17-8 ) None observed Sub-ortholognitioiis 16-6— 20-0 J * Two cases are not included here (Nos. 167 and 175) as the hydrogen appears abnormally low, namely 2-12 and 2-17 per cent. With the exception of No. 169, in which the percentage of hydrogen is 2-11, no other coals, even in Pembrokeshire, show less than 3-0 per cent, of hydrogen. The C/H ratios are respectively, 43-8, 43-0 and 45-1. Had they contained 3 per cent, of hydrogen the C/H ratios would have been 31-0, 31-0 and 31-7. They were communicated in MS., so it is possible a copying mistake was made, or they may have been selected for some purpose or investigation unknown. 64 THE COALS OF SOUTH WALES. Semi-bituminous Genus. Species. Possible limits of C/H ratio. Observed lim'ts. No. of cases. (Anthraoitio) Ortho-semibituminous Sub-metabituminous Sub-orthobituminous Sub-parabituminous Sub-metahgnitious Sub-ortholignitious 18-7— 21-2 ? 18-2— 20-7 17-8— 20-3 17-4— 19-7 16-8— 19-3 16-0— 18-7 15 0— 17-8 20-2 18-4 to 20-4 18-2 to 20-2 17-7 to 18-8 17-8 to 18-2 None observed 16-6 1 29 22 3 3 1 Bituminous Genus. (Anthraoitio) 16-1— 19-0 ? 17-6 1 Pseudo-bituminous 15-7— 18-6 17-4 to 18-2 3 Meta-bituminous 16-3— 18-2 15-7 to 18-0 12 Ortho-bituminous 15-0— 17-8 15-2 to 17-6 34 Para-bituminous 14-5— 17-4 15-1 to 17-0 19 Meta-lignitious 13-8— 16-8 15-2 to 16-7 4 Ortho-lignitious 12-9— 16-0 14-6 1 Per.-bituTninous Genus. (Anthraoitio) (Carbonaceous) ... Per-metabituminous Per-orthobituminous Per-parabituminous Per-metalignitious Per-ortholignitious 13-9 ?— 16-2? 16-1 and less 15-7 and less 15-3 and less 15-0 and less 14-5 and less 13-8 and less [ None observed 13-4 13-4 to 14-7 12-9 to 14-7 [ None observed Summary of observed limits for the various Genera. Anthraoitio genus 22 and over Carbonaceous genus ... Semi-bituminous genus Bituminous genus Per- bituminous genus 20-3— 23-35 i 16-6— 20-4 14-6- 18-2 12-9— 14-7 I Overlap 1-35* [ Overlap -1 I Overlap 1-6 f Overlap -1 Uut of the 321 analyses available 12 are only proximate analyses, so it is impossible to names these on Seyler's or the C/H classifications. Of the 309 where it is possible to name on these classifications, the C/H ratio shows, on the limits adopted by the United States Geological Survey : — Anthracites Semi-anthracites Semi-bituminous Bituminous I. ... Bituminous II. Bituminous III. 57 57 63 65 62 5 * For example, a coal with C/H ratio between 22 and 23-35 might belong to either the anthracitic or carbonaceous genus. 65 CHAPTEE VIII. Explanation of the Iso-anthracitic Chaets (Plates 3 to 8). By A. Strahan. The object of these charts is to show areas of equal anthra- citism in each seam or group of seams. The positions of the samples on the analyses of which the charts are founded are indicated by numbers corresponding to those in the table on pp. 14-30. The degree of anthracitism of each sample is expressed by the factor representing the relation of carbon to hydrogen, i.e., the C/H ratio, that factor being more suitable for the purpose than any other, for the reasons explained on p. 62. The figures in the table which give that relation range from 13 to more than 31, and for convenience the lines corresponding to tha numbers 14, 17, 20, 23, 26, and 29 have been selected for illustration of the iso-anthracitic areas on the charts. The iso-anthracitic line 17, for example, is drawn through all those localities in which it is calculated that the C/H ratio would equal 17. The space between lines 14 and 17, in any one seam, may be regarded as corresponding to the area in which that seam has the character of house-coal, but begins to assume that of steam- coal, that is belongs to the Bituminous Genus of the Table on p. 64; while that between lines 17 and 20 includes the passage into steam-coal, and steam-coal, that is the Semi-bituminous Genus of the Table. Lines 20 to 23 include steam-coal of the Carbonaceous Genus. Line 23 marks the oncoming of anthra- cites, and from line 24 (not shown on the charts) upwards the coals may be regarded as true anthracites. The iso-anthracitic lines have, of course, no relation to the outcrops of the seams. In fact, a line is sometimes continued a little beyond the area in which the seam to which it relates exists, or even beyond the margin of the coal-field, where the evidence obtainable in the coal-field suffices to indicate the position it occupied before the coal-field was reduced to its present dimensions by denudation. Plate 3. The chart forming this plate is founded upon analyses of the lowest veins, namely, those which occur below the datum- line in Plate 2. Taken from east to west, the group includes the following seams : — Old Coal. Meadow Vein. Cribbwr Vein. Four Feet Vein (Morfa). Four Feet Vein (Cl3me Valley). Yankee Vein. Three Feet Vein (Clyne VaUey). Brass or Peacock Vein. Yard Vein. Middle Vein. Lower Vein. Gnapiog Vein. Trigloin Vein. Lower Pumpquart Vein. Lower Trichwart Vein. Charcoal Vein. Little Vein. Lower Level Vein. Timber Vein. The samples for analysis were obtainable from near the margin 66 THE COALS OP SOUTH WALES. only of the coal-field, none of the veins being accessible at present in the interior. The seams as a group lie on the same horizon, near the base of the Coal Measures, and are included in a thickness of about 500 feet of measures. The Timber Vein may correspond to the Stanllyd, which is taken as the datum- line in Plate 2. The iso-anthracitic line 17 is determined by the analyses of the Old Coal and Meadow Vein towards the east, and by analyses of the Cribbwr Vein and the Clyne Valley coals in the South Crop. The direction in which the anthracitic character develops is foreshadowed by the analyses of both the Old and the Meadow seams, but evidence of the position of line 20 is wanting. The position of line 26 is indicated by analyses of the Brass or Peacock Vein, except that Nos.'62 and 47 with ratios of 24-03 and 23-74 do not fall into their position. On the other hand No. 168 is situated between them and shows a ratio of 29-12, which is more in accordance with expectation. The position of line 29 is proved by analyses of the Pumpquart and Triquart Veins. The Pembrokeshire analyses lie near, or on the higher side of, line 29, and correspond to, or slightly surpass, the highest stage t)f anthracitism reached in Carmar- thenshire. Plate 4. This chart is founded on analyses of the. vein which, in -different parts of the coal-field, passes under the following names: — The Black or Eock (eastern part), Eas-las or Nine Feet (East Glamorganshire), Nine Feet or Big (North Crop on the borders of Glamorganshire and Brecknock), probably the Stanllyd and Carway Big (Carmarthenshire), and possibly the Timber Vein (Pembrokeshire). This coal-seam being more widely recognisable than most others, has been selected as the datum-line in Plate 2, and is more fully illustrated than the rest in the analyses. Analyses Nos. 167, 169 and 175 have been omitted for the reason stated on p. 63 (footnote). The iso-anthracitic line 17 is well determined in Monmouth- shire, but, so far as regards the South Crop, is founded only on an analysis of the Nine Feet at Morfa (No. 27), of the Nine Feet atLlynfi (No. 23), and of the Nine Feet at locality No. 9. It coincides approximately with the line 17 in the underlying seams (Plate 3), so far as that line has been located. The iso-anthracitic line 20 follows a nearly parallel course, but is bent north-westwards to accommodate an analysis of the Eas-las at Dowlais (No. 22), quoted by Dr. Percy.* Possibly this bend would disappear, or be modified, if further analyses east of locality 22 were available, but there is evidence of a similar bend in lines 17 and 20 in the Four Feet Seam also (Plate 5). The recent analyses show that lines 17 and 20 both extend further to the south-east than was anticipated when the first edition of this Memoir was published. Line 23, so far as it is determined by analyses of the Nine Feet at liirwain (No. 24) and the Nine Feet of locality 19, follows a normal course, but its westward continuation is not proved. EXPLANATION OF PLATES. 67 Line 26 is founded on a series of analyses of the Big, Nine Feet, or Stanllyd Vein of the anthracitic region. The bend in it may be due partly to experimental error in analysis, and may have little significance. Line 29 is not reached in the Big or Stanllyd in Carmarthen- shire, but its position is indicated by analysis No. 13, and it is touched at Hook (No. 198) in the Timber Vein, which may correspond to the Stanllyd. Plate 5. A group of veins which lies not far above the Ras-las or Nine Feet Seam in Monmouthshire includes the EUed, Big and Three Quarters. In Glamorganshire the Two Feet Nine, the Aberdare Four Feet, and the Aberdare Six Feet occupy a corresponding position with respect to the Nine Feet, but cannot be correlated individually with the Monmouthshire seams. For the Three Quarters Seam seven analyses are available, but they give discrepant results. In Ebbw-fach, Analyses Nos. 92 and 93 show carbon-hydrogen ratios of 14-62 and 17-58 ; south of Blaenavon, Analyses Nos. 95 and 96 show ratios of 15-24 and 16-89; near Pontypool, Analyses Nos. 94, 97, 189 show ratios of 17-25, 17-10 and 20-51. Having regard to these discrepancies it appears to be impossible to fix the positions of the iso-anthracitic lines with sufficient precision for insertion upon the chart. The information, so far as it goes, points to an average ratio of 16-1 in Ebbw-fach, of 16-06 south of Blaenavon, and of 18-29 near Pontypool, and there'fore to the ratio 17 in the Three Quarter Vein, falling approximately into line with the ratio 17 in the Aberdare Veins of Grlamorgaashire. For the Big Vein we have Analysis No. 39 with a ratio of 13-43 in Ebbw-fach, and Analyses Nos. 110, 111 and 215 with ratios of 17-15, 16-81 and 16-90, near Pontypool. The Big Vein appears, therefpre, to be more bituminous in any one locality than the Three Quarter Vein a few yards below. The Aberdare group admits of more precise treatment. In the Four Feet and Six Feet Seams line 20 is fixed by a number of analyses, but the position of line 17 across the Llynfi, Garw and Ogmore Valleys can only be estimated, partly owing to the difficulty of identifying the seams. In the north-east quarter of the coal-field lines 20 and 17 in the Four Feet Seam are located by Analyses 85 and 87, but it must be noted that one analysis, No. 86, showing a carbon-hydrogen ratio of 18-93 in the Upper Four Feet of Dyffryn, falls far on the wrong side of line 20, a fac? for which no explanation is forthcoming. It seems possible, however, that the hydrogen is too high, as with a percentage of 4-91 of hydrogen, a greater percentage of volatile matter than 16-23 might be expected. For the Two Feet Nine Seam Analyses Nos. 78, 79 and 219 are available. From No. 219 it appears that line 20 in the Two Feet Nine coincides with the same line in the Aberdare Six Feet, while Nos. 78 and 79 indicate the position of line 23 and show that the approach to an anthracitic condition is less 68 THE COALS OF SOtJTH WALES. rapid in the Two Feet Nine than in the underlying Four Feet and Six Feet Seams. In and to the west of the Vale of Neath there occur some well-known seams on the same horizon as the Aberdare group, as shown in Plate 2. Here again the correlation of the seams individually with those of the Aberdare group is attended with doubt, though it is generally thought that the Stwrain corre- sponds to the Two Feet Nine Seam. Three lines are shown in the Vale of Neath seams. They are founded on analyses of the Four Feet and of the Eighteen Feet, which lies 10 to 14 yards above the Four Feet seam. Both coals are placed on the market as anthracites, this part of the Vale of Neath being commonly regarded as lying on the margin of the anthracitic region. The evidence furnished independently by these seams indi- cates that the iso-anthracitic lines trend north-westwards, as though there were a local anthracitic centre near Glyn Neath. This trend is not observable in the underlying seams (Plates 3 and 4), but is maintained in an overlying seam, the Red Vein, which is also shown on Plate 5. Though there is no doubt that further analyses would show that the lines soon resume their normal westerly trend, yet this agreement in an unusual direc- tion in so many veins, taken as they were independently, is too pronounced to be ignored. It indicates that there are local pecularities in the distribution of the anthracitic character in certain seams or groups of seams, which are difficult to explain on the supposition that the seams were originally alike, but were subsequently anthracitised by one common cause. The Red Vein here referred to is not to be confused with the Red Vein which corresponds to the Three Quarter Coal near Pontypool. It is recognised as a workable seam from the Dulais, a tributary of the Neath, to near Ammanford, and is regarded as an anthracite, but as approaching a steam-coal in places. The analyses, Nos. 128-135, enable the iso-anthracitic lines 23 and 26 to be fixed with some precision from Dillwyn in the Dulais valley to Cawdor, Cwmamman. On comparing the Red Vein with those below it, it will be seen that the line 26 in the Red Vein approximately coincides with the line 23 in the Eighteen Feet Vein, and is south of the line 23 in the Cornish Vein. This indicates that the Red Vein becomes anthracitic in a region where the veins several hundred feet below it have not yet assumed that character. Here again we have an exception to the rule that the lower seams are the earlier to become anthracitic, and a further illustration of the fact that some seams betray a certain individuality in their behaviour as regards their assumption of the anthracitic character. The position of analysis No. 124 has been inserted in this chart. The analysis gives the composition of the Lower or Welsh Vein of Cwm Clic according to Percy, and the carbon- hydrogen ratio is 25-4, which indicates that the seam is more anthracitic than the Red Vein, though it lies above it. Con- firmation of this is desirable. The Green and Drap Veins, which lie 25 and 107 yards EXPLANATION OP PLATES. 69 respectively above the Big Vein, are also shown upon this chart. In the Green Vein the positions of lines 23 and 26 are deter- mined at localities 190 and 146, and that of line 20 in the Drap Vein at locality 145. The lines 20 in the Drap, 23 in the Green, and 25 in the Big Vein (Nos. 12, 144) approximately coincide, while line 26 in the Green lies a mile north of line 26 in the Big Vein. This, of course, means that in any one vertical section the Draj) would be more bituminous than the Green and the Green than the Big, in accordance with the rule mentioned on p. 2. But, on the other hand, on comparing Plate 4 with Plate 3, we find that the line 23 in the Big or Nine Feet Vein lies six miles south of the line 23 in the Brass Vein, which is about 20 yards below, and again that the line 26 in the Big or Nine Feet lies distinctly south of the line 26 in the lower veins. This means that the Big in any one vertical section would be more anthracitic than some of the seams below it. The rule referred to is therefore not universally true. The Green and Drap Veins correspond approximately in position to the Vale of Neath and Aberdare seams illustrated in the plate. Their composition confirms the supposition pre- viously mentioned, that the normal trend of the iso-anthracitic lines is soon resumed west of the Vale of Neath. Plate 6. Plate 6 shows the iso-anthracitic lines in the seam known in different areas as the Tillery or Red Ash, the Rock-fawr, the Brithdir, the Pen-y-graig or No. 2 Ehondda. It may be com- pared with the chart of the Ras-las Vein in Plate 4. In both the anthracitic character develops steadily north-westwards, and, except for irregularities in the curves, which are drawn to suit certain analyses, and which might be modified if the series of analyses were more complete, there is a fairly close coinci- dence of lines 14, 17 and 20 in the higher seam with lines 17, 20 and 23 in the lower seam. This relation of the lines gives data for calculating the vertical rate of decrease of anthracitisa- tion for certain localities. Thus in Monmouthshire a decrease of 3 (from 20 to 17) in the carbonrhydrogen ratio occurs in a vertical distance of 852 feet, giving a rate of 1 in 284 feet. But near locality No. 179 in the Brithdir, and locality No. 7 in the Ras-las Vein, the vertical distance is 1,350 feet, a ad the decrease of 3 (from 23 to 20) in that distance gives a rate of 1 in 450 feet. Again at Bronbil (locality Nos. 55 and 59) the mean of two Admiralty analyses gives a carbon-hydrogen ratio of 16-9 in the higher vein, while at Morfa (locality No. 27) the ratio is 16-2 in the Nine Feet Vein, about 2,600 feet below the Bronbil seam. Here, therefore, the higher and the lower seams are about equally bituminous, a state of affairs which probably prevails throughout the extreme southern margin of the coal-field. The analysis of the No. 2 Rhondda Vein (No. 60) which lies nearest to the anthracitic region is quoted from Percy, who gives the seam as the Upper or Pen-y-graig Vein of Cwm Clic. It fixes one point on the line 23, but leaves us in doubt whether 70 THE COALS OF SOUTH WALES. that line takes the north-westward trend which is observable in the Eed and other veins of Plate 5. It proves, however, that the No. 2 Ehondda seam reaches the anthracitic degree indi- cated by the line 23 further south than do either the Eed or the Cornish Four Feet Veins, and thus furnishes another exception to the rule that the lower seams are the more anthracitic. So far as this locality is concerned the rule is generally reversed. On Plate 6 an analysis of No. 3 Ehondda Seam also is entered. It indicates that at Penrhiw (localities Nos. 125, 196) that seam is slightly less bituminous than the Forest Vein which lies about 77 yards above it. In the Graig Seam, of which we have two analyses, the line 20 agrees closely with the line 20 in the No. 2 Ehondda Seam, although the Graig Seam lies upwards of 150 yards below the No. 2 seam. A projiounced loop towards the south-east in line 20 in the No. 2 Ebondda Vein is neces- sitated by analysis No. 236. Lines 17 and 14 in the No. 2 Ehondda Vein have been re- drawn to accord with the recent analyses. Line 17 in its western part is determined by analyses Nos. 55, 59, 54, 242 and 246. That it then bends sharply southwards is proved by a comparison of analyses Nos. 246 and 225, and it is to be noted that the effect of the bend is to preserve parallelism between lines 17 and 20. The return bend of line 17 to its original range is shown by analyses Nos. 204, 214 and 179. The exis- tence of a south-eastward loop in the line in this part of the coal-field was indicated in the first edition of this Memoir, but has now been determined with greater precision by aid of the recent information. Line 14 has been redrawn so as to pass southwards of the localities of analyses Nos. 233, 232, 224, 221 and 237. The position on the eastern margin of the coal-field is estimated from analysis No. 208. The Hughes Vein, which is also illustrated on Piate 6, forms the lowest and most important member of a group which includes also the Slatog, Curly, and Eotten or Bodwr Veilis, and has been extensively worked from near Glyn Corwg to the western end of Gower. It lies from 450 to 500 yards above the No. 2 Ehondda Seam or its local equivalent. A comparison of the lines in the Hughes Vein with those of the No. 2 Ehondda Seam shows that the line 20 in the Hughes would, if prolonged, join line 20 in the No. 2 Ehondda, but that line 17 lies much closer to line 20 in the Hughes group than it does in the No. 2 Seam farther east. This implies that the change in character is more rapid in the west, a conclusion of which we shall obtain further evidence. Plate 7. The Mynyddislwyn, or Bedwas Vein, is well known as a house coal in Monmouthshire, but it occurs in detached parts only of the coal-field and the data permit no more than an approxi- mate determination of line 14. Five analyses, Nos. 217, 73, 213, 180 and 72 are available for comparison. While they show that line 14 is not far west of the position of the same line EXPLANATION OF PLATES. (i in No. 2 Rhondda (Plate 6), they are consistent in indicating that the Mynyddislwyn Vein becomes more bituminous in a north-westward direction. As already explained, the Wernffraith, or Swansea Four Feet Vein, is taken to be the equivalent of the Mynyddislwyn Vein in preference to the Graigola, or Six Feet Vein, which lies 250 yards below the Four Feet. The analyses enable us to trace the line 20 for some miles. It follows the same general direction as line 20 in the Six Feet Vein, but runs into it, and crosses it to the west, the evidence for this being an analysis of Ward's Fiery Vein* (No. 104) quoted in the Admiralty Report. That analysis gives a carbon-hydrogen ratio of 22-4, as com- pared with 17-9 in the Llanelly Fiery (No. 105) to the west of i^, and with 19:1 in that vein (No. 101) to the east of it, although Ward's Fiery Vein lies 218 yards above the Llanelly Fiery Vein. The exact position, however, of line 20 towards the west must in any case be regarded as doubtful, inasmuch as it is founded on one analysis only. The Graigola, or Six Feet Vein, is 270 to 350 yards above the Hughes Vein. The iso-anthracitic line 20, as determined by several analyses of the Graigola Vein, runs slightly north of the line 20 in the Hughes Vein for part of its course, and turns northwards towards the east so as to suggest the existence of a local anthracitic centre between Swansea Vale and Pontar- dulais. Combining this chart with that of the Aberdare Four Feet (Plate 5), we obtain the relative positions of two local anthracitic centres with a comparatively bituminous area extending northwards between them. Our information does not suffice to prove that either vein would show both centres, but it is likely that the Aberdare Four Feet would do so, for the north-westerly trend of the line 20 shown in Plate 5 is cer- tainly replaced by a westerly or south-westerly trend a little further west. An analysis (No. 122) of the Swansea Three Feet Vein is entered on this same chart. That vein lies 13 yards below the Six Feet, but appears to be slightly more bituminous than it, on comparison of analyses Nos. 100 and 122. The Swansea Five Feet lies between the Four Feet and Graigola (Six Feet) Veins, and 140 yards above the latter. The analyses are limited to a small area : two from the same colliery give a carbon-hydrogen ratio of 18-8 in the Five Feet Vein (No. 74) as compared with 1948 in the Graigola (No. 100), which gives a vertical decrease of -38 in 140 yards in the carbon- hydrogen ratio, or 1 in about 1,000 feet. The position of line 23 is indicated by one analysis only (No. 76). The iso-anthracitic lines in the Five Feet Vein are not inserted on the plate for want of space. The rate at which the bituminous character decreases north- * The Kery Vein of Llanelly is well known to correspond to the Graigola or Swansea Six Feet, but " Ward's Kery Vein " is the name given on old plans to the Llanelly, or Box Big Vein, which corresponds to the Swansea Four Feet. The Fiery Vein of Oldcastle (Analysis No. 105), on the other hand, must be the Llanelly Fiery, inasmuch as the Llanelly Six Feet, or Box Big Vein, is " in the wind " at that colliery. 72 THE COALS OF SOUTH WALES. wards has been determined with great accuracy in one locality in this vein. Three sets of samples (Nos. 152-160) were col- lected with this object in view from three spots situated in a line running nearly north and south. Locality A (Plate 8), which yielded the samples 158, 159, and 160, was 520 yards N. 11° W. of locality B, which yielded the samples 152, 153, 154; Locality B was 1,310 yards N. 22° E. of Locality C, which yielded the samples 155, 156, 157. The results are shown in the following table and in Plate 8 : — Swansea Five Feet Vein. Locality A. Carbon-hydrogen ratio. Locality B. Carbon-hydrogen ratio. Locality C. Carbon-hydrogen ratio. Top Coal Middle Coal ... Bottom Coal ... 21-10 21-15 20-85 20-81 20-89 20-58 18-98 18-77 18-67 Mean 21-03 20-76 18-807 These figure's show that the change becomes more gradual as true anthracite is approached. Thus from C to B the rate on the mean values is one unit of the carbon-hydrogen ratio gained in 604 yards, while from B to A the rate is one unit in 1,813 yards. The change in the part of the coal-field from which these samples (Nos. 152-160) are taken is certainly more rapid than it is in the eastern part, but data for an exact comparison are lacking, no other opportunity having occurred of obtaining samples from the same vein at a series of suitable spots. 73 CHAPTEE IX. Origin of Anthracite. By A. Steahan. MusiiET was the first to attempt an explanation of the varia- tions in the composition of Welsh coals. He pointed out that coals of different qualities are associated with similar strata, that the coal only, and not the accompanying measures, is changed, and that there is no contact of trap-rocks to account for the phenomena. He found difficulty in the supposed growth of a wide variety of plants in a limited space, and concluded that " fermentation and the degree of temperature thereby excited during the period of transition — but not that of submersion — from wood or vegetable matter into coal, may . furnish the most rational clue to the mystery."* De la Beche alsjo sketched generally the distribution of anthracite, and wrote: "Taking the coal measures of South Wales and Monmouthshire, we have a series of accumulations in which the coal beds become not only more anthracitic towards the west, but also exhibit this change in a plane which may be considered as dipping to the S.S.E. at a moderate angle, the amount of which is not yet clearly ascertained, so that in the natural section afforded we have bituminous coals in the high grounds and anthracitic coals beneath." He found nothing to lead him to infer that there was any original difference in the coal, and attributed the anthracitisa- tion to subsequent change. The change he believed to be due to the volatile compounds formed by decomposition having carried off relatively greater proportions of the hydrogen and oxygen than of the carbon. The view that it was due to disturbance of the strata was, in his opinion, untenable, inas- much as the Coal Measures at Mertliyr Tydfil were not more disturbed than they were at Pontypool, nor at Hirwain than they were at Pyle. The bituminous coal of Vobster, moreover, near the Mendip Hills, was far more contorted than a great proportion of the anthracitic coal of South Wales. He con- cludes by referring to long-continued high temperature as capable of effecting the change, and points out that if a portion of the coal-area was depressed below the other parts, and thus brought more within the influence of internal heat, decomposi- tion in that part might have proceeded faster than in other parts. The fact that the lower beds were more anthracitic than the upper beds pointed to an influence acting from beneath and not from above. t In 1859 Dr. J. P. Bevant described the distribution of anthracitic and bituminous coals, and attributed the anthra- citisation to " trap-rocks far below the surface, which have never appeared." The alteration was believed by him to have * ' Papers on Iron and Steel,' London, 1840. t Memoirs of the Oeol. Survey, Vol. i, pp. 217 to 221, 1846. X The Geologist, vol. ii, p. 75, 1859. 74 THE COALS or SOUTH WALES. been effected before the " Upper Measure Coals " were deposited. Mr. Thomas Joseph,* in 1870, classified the coals according to their behaviour when burning, and showed on a map the distribution of the various classes in the eastern part of the coal-field. The gradual progress of the change from east to west was clearly recognised, but, in addition, certain faults were credited with throwing in a higher stage of anthracitisa- tion. Mr. Joseph noted also " the regular gradation of change upwards from the lowest to the highest seams." He concluded that the coals had originally been bituminous or " dark- smoky," and had been subsequently altered, the measure for the change being marked by the progressive development of " slip cleavage " in the coal seams. The change was attributed to magnetic or galvano-magnetic action, and was considered to have been long posterior to " the occurrence of faults." In 1877 Mr. E. T. Hardmant attributed the anthracitisation to internal heat, caused by intrusion of plutonic rocks. Prof. Galloway,t in 1884, classed the coals as " long-flaming dry coal above ; the caking coals in the middle ; and the dry steam, or anthracitic, coals at the bottom." The loss of bituminous matter was attributed to the seams having been covered by a greater thickness of strata, and consequently exposed to a higher temperature, in the anthracitic region than elsewhere. In 1900 Mr. C. A. Seyler§ published the results of a large number of analyses and discussed in great detail the classifica- tion of coals, but did not touch upon the causes of anthra- citisation. In 1903 Mr. John Roberts, || in evidence given before the Royal Commission on Coal Supplies, described the distribution of bituminous, semi-bituminous, and anthracitic coals in South Wales, and estimated the area occupied by each of these classes. Mr. David BurnsH discusses various objections to the theories in which anthracite is supposed to have resulted from the loss of volatile matter in a bituminous coal, and comments on the fact that in going from coking coal to anthracite there is a diminution of ash. He suggests that chlorine disengaged by volcanic action combined with the hydrogen of the bitu- minous coal, while part of the hydrogen combined with the oxygen of the coal to form water. The free hydrochloric acid thus formed carried i^th it some portion of the ash as chlorides. This hypothesis is not well supported by evidence. There was thus a general agreement that the anthracitic * Trans. 8. Wales Inst. Eng., vol. vii, p. 137, 1872. t Journ. Roy. Oeol. Soc. Ireland, New Series, Vol. iv, p. 200, 1877. X Trans. Cardiff Nat. 8oc., vol. xVi, p. 20, 1885 ; and ' Course of Lectures on Mining.' Pub. by the S. Wales Inst. Eng., Cardiff, 1900. § Proc. S. Wales Inst. Eng., Vol. xxi, p. 483, 1898-1900, and vol. xxii, p. 112. See also ' Analyses of British Coals and Coke,' Introduction, Coll. Giiardian, 1907, and ' Practical Coal Mining,' vol. i, p. 07, London, 1907. 1 1 Roy. Com. on Coal Supplies, 2nd Rep., 1904, p. 302, and Plates 21, 22,' 23. T[ Trans. N. of England Inst. M.E., vol. liv, 1904, Appendix 4, p. 1. bklGIN OF ANTHRACITE. 75 character had resulted from a change effected upon coals which had been originally bituminous. Three explanations of the change had been put forward, namely, that the anthracitic seams had been more deeply buried and consequently exposed to a higher temperature, that they had been altered by the neighbourhood of plutonic rocks, and lastly, that they were more affected by slip-cleavage. To all of these theories serious objections present themselves. In the part of the coal-field where the measures are thickest, and where the seams were more deeply buried in Carboniferous times, the coals are bituminous. The same remark applies also to the covering of Secondary rocks which was subsequently spread over them. That covering was thickest in the southern and bituminous region where part of it still survives, and thinnest, if indeed it extended at all, over the northern and anthracitic part. The trap-rocks of Pembrokeshire, which were appealed to as showing the probability of similar molten masses having pene- trated under parts of the coal-field, are of pre-Carboniferous age, and therefore can have had no effect upon the Coal Measures. Moreover, coals, where whin-sills have come into contact with them in other coal-fields, have been coked and not anthracitised, while at the same time the percentage of ash has largely increased. Slip-cleavage is not developed in anthracitic seams, nor does the theory that anthracitisation is due to the escape of volatile matter accord with the fact that the lower seams are generally the more anthracitic. The hypothesis that the anthracitisation was due to distur- bance of the strata may be put aside in consideration of the facts mentioned by De la Beche, and in view also of the distribution of anthracite in Ireland and elsewhere. -In taking the view that the differences between the anthra- citic and bituminous coals in South Wales are mainly due to original differences in composition we are guided by the follow- ing considerations : — 1. While the charts confirm the general conclusions which have long been held on the distribution of the various classes of coal, they show further that some seams, or some groups of seams, possess a certain individuality. In some there are local anthracitic areas of which no evidence appears in others; the rate also at which the change to anthracite takes place differs in different seams. From a combination of these causes the rule that every seam is mora anthracitic than the one above it is by no means universally true. Again, not only do certain seams differ from those above and below them, but bands in the same seam may show considerable differences in composition. These characters lend no support to a theory of the seams having been altered by one common cause acting subsequently to their deposition, such, for example, as regional metamorphism. 2. The iso-anthracitic lines show no definite connection with 76 THE COALS OF SOUTH WALES. the faults and disturbances. The dislocations of the strata m South "Wales fall into three systems : — (o) The nearly east-and-west disturbances which traverse Somerset, Devon, and the south of Ireland, involving within their northern margin the Vale of Glamorgan, Gower, and South Pembrokeshire. (6) The west-south-west system which runs for the most part north of the coal-field, but branches of which traverse the Vale of Neath, the valley of the Tawe and part of the anthraoitic region. (c) The faults which range across the coal-field with directions ranging from south to south-south-east. Of these three systems the east-and-west (a) and the west- south-west (h) are similar in their characters. Both affect broad belts of country, and are accompanied by sharp folding and over-thrusting, yet one of them (a) traverses part of the coal- field where the seams are bituminous. Though the strata may be vertical or even inverted, and sharply folded, as in Gower, yet the coal seams retain the composition proper to that part of the coal-field. That the other (b) traverses the anthracitic region appears therefore to be an accidental coincidence, though the fact that the most easterly appearance of a west- south-west disturbance in the Vale of Neath agrees in position with the on-coming of the anthracitic character, was at first sight strongly suggestive of a connection between the two. The north-and-south faults (c) have a local effect upon the quality of the coal. The nature of the alteration is not brought out in any of the analyses quoted in this volume, the object of which is to show the normal quality of the coal, but is reported to consist in the loss of bituminous matter. The fact, however, that the iso-anthracitic lines run approximately at right angles to the faults sufficiently disproves any connection between the two. Moreover, the nortt-and-squth faults are neither so large nor so numerous in the anthracitic parts as in some of the bituminous parts of the coal-field. The north-and-south faults sometimes throw into opposition coals of different degrees of anthracitisation. The vertical dis- placement effected by these faults often amounts to 200 yards, and in exceptional cases to 800 yards. The seams now brought face to face were, therefore, originally separated by a thickness of strata equal to the throw of the fault, and differ in accor- dance with the general rule that the lower seams are the more anthracitic. No example has come to light of the same seam permanently changing in degree of anthracitisation on the opposite sides of a fault. It is to be inferred from these facts that the anthracitisation was prior to the faulting. 3. The anthracitisation is obviously not connected with the existing outlines of the coal-field, as determined by denudation. The anthracitic region appears to have lain principally outside the north-western margin of the main coal-field and to the west of it, in Pembrokeshire. Most of it has been removed by denudation, but so far as the surviving part of it enables us to judge it must have extended in a direction slightly south of west. The form of the iso-anthracitic lines suggest that it never extended eastwards beyond Monmouthshire, if so far ; its ORIGIN OF ANTHRACITE. ( < westward limit is, of course, unknown. Again, there is no connection between anthracitisation and depth from the present surface. Slight changes in the quality of the coals are observable at their outcrops, but it has not been proved that these changes are in the direction of anthracitisation. On the other hand, in the bituminous region the coals continue to be bituminous so far down as they have been followed, while in the anthracitic region the coals are anthracitie up to their out- crops. It appears, therefore, that the coals had assumed their present character before either the outlines or the surface-con- iiguration of the coal-field had been determined by denudation. 4. A feature in the anthracites which is brought out by the collation of analyses consists in their freedom from ash as com- pared with the bituminous coals. The fact is important from the point of view of the origin of anthracite, for obviously the alteration of a bituminous coal into an anthracite by the loss of bituminous matter from any cause would increase the per- centage of ash. The comparative freedom of anthracite from ash has long been known, and has been alluded to by several writers. The fact is brought out by Mushet's analyses,* and is commented on by Richardson. t Mushet's analyses are proximate only, and therefore do not yield data for the C/H ratio. On classifying them according to the fuel-ratio, we find that the average percentage of ash ranges from 3-43 in 96 analyses of bituminous coals, to 3-66 in 56 analyses of semi-bituminous, 2-61 in 25 analyses of semi-anthracite, and 2-50 in 16 analyses of anthra- cite. That the fuel-ratio is not the best basis of classification has already been shown (p. 60), but it suffices to distinguish roughly the four classes named. MellyJ gives as one of the distinctive features of anthracite a low percentage of sulphur and ash. Mr. David Burns also calls special attention to the small proportion of ash in anthracite. § By ash is meant all the incombustible residue. This includes not only any slaty films which are too thin -to be picked out from the coal, but all pyrites, sulphates, and carbonates which line cracks in the coal, or are disseminated through the coal, as well as the inorganic material contained in the tissues of the plants which formed the coal. In the analyses quoted on pp. 14-30 no attempt has been made to discriminate between these different sources of ash, and it is questionable whether much would be gained by doing so. The minerals which line cracks in the coal are as likely as not to have been derived from the coal itself, and, at any rate, to separate them out before analysis would give a wrong idea of the coal as it is put on the market. The sulphur, moreover, could never be completely eliminated,, as was shown by Percy in 1875.11 The presence of * ' Papers on Iron and Steel,' by David Mushet. Ix)ndon, 1840. t Proc. Inst. C.E., Vol. viii., 1849, p. 98. % Trans. N. of England Inst. M.E., Vol. xxx, 1882, p. 175. i, Trans. N. of England Inst. M.E., Vol. liv, 1904, Appendix 4, p. ]. II ' Metallurgy," p. 568. f2 78 THE COALS OF SOUTH WALES. alumina in the ash would seem at first sight to prove that the ash was partly of sedimentary origin. But it has been shown to be "a characteristic and abundant constituent of the ash of many, if not all, the species of terrestrial Lycopodia ', ■ • ■ that it is present in notable quantity in at least one species of tree-fern though practically absent in others ; and that it occurs in insignificant amount ... in almost every plant in which its presence has been carefully sought for."* For these reasons we will take the analyses in their original forms in considering the distribution of ash, remarking merely that the great differences of ash in some of the coals, and especially in those of the bituminous part of the coal-field_, may be partly due to other causes than difference in the original composition of the coals themselves. Our conclusions must be formed on averages rather than on individual samples. For the purposes of this inquiry we can use only those seams or groups of seams which can be traced through both the bituminous and the anthracitic areas. Of these the most prominent is the Ras-las and its supposed equivalents, for though the seams below the Ras-las persist as a group, they are not traceable individually. The diagrams forming Plate 9 show the result of plotting a line to represent the percentage of ash existing in coal for each unit of the carbon -hydrogen ratio. The anthracites occupy approximately the left-hand half of the table, the right half showing steam- and house-coals. In Diagram 1 all available analyses of the Ras-las Vein (or of its equivalents under other names) have been inserted. The percentages of ash shown are those actually proved in the analyses, and they are placed in position according to the proved carbon-hydrogen ratio of the coals. The diagram, there- fore, in the first place illustrates the variations which have been recorded in the ash-contents of specimens of the same seam from different localities. In the second place it shows that the variation is greater towards the bituminous end than towards the anthracitic end of the scale, the range in the one case being from 0-7 to 6-2 per cent, and in the other from 2-0 to 11-60 per cent, of ash. Thirdly, it shows that the average percentage of ash increases considerably towards the bituminous end. Single exceptional analyses are responsible for most of the violent zig-zags in the line, and without doubt if a larger number was available and exceptions were merged in averages, the line would tend to become a more or less steady gradient from approximately 2-0 at the anthracitic end, to approximately 7-0 at the bituminous end of the diagram. In Diagram 2 the seams below the Ras-las are illustrated. As no one of the seams is recognisable throughout, it became necessary to combine them and to deal with averages. All available analyses have been utilised, and the mean of those which fall between two adjoining units of the carbon-hydrogen ratio has been calculated, both as regards that ratio and the percentage of ash. Thus the means m the column 29-28 are * A. H. Church, Proc. Boy. Soc., Vol. xliv, 1888, p. 127. ORIGIN OF ANTHRACITE. calculated from three analyses, namely, Nos. 303, 312, 318. The actual values obtained by the grouping of the analyses and represented on the diagram are as follows : — Column. Number of analyses available. Mean C/H ratio. Mean percentage of Ash. Above 31 1 31-50 1-0 31—30 1 3006 •8 30—29 2 29-38 2-0 29—28 3 28-33 3-0 28—27 5 27-50 2-0 27—26 7 26-34 1-8 26—25 11 25-60 2-0 25—24 3 24-50 1-8 24—23 1 23-74 2-4 18—17 2 17-49 4-1 17—16 6 16-54 4-1 16—15 3 15-82 3-1 The diagram shows that an approximate average of 2 per cent, of ash accompanies the anthracitic state of the seams as compared with an average approximately twice as great in the bituminous state. In Diagram 3 all available analyses of all seams* have been combined by the same method as in Diagram 2. The actual values obtained by the grouping of the analyses and repre- sented on the diagram are as follows: — Column. Number of analyses available. Mean C/H ratio. Mean percentage of Ash. Above 31 1 31-50 1-5 31—30 2 30-48 11 30—29 4 29-44 1-4 29—28 8 28-49 2-48 28—27 15 27-38 2-09 27—26 21 26-44 2-91 26—25 30 25-53 2-42 25—24 14 24-49 2-40 24—23 12 23-44 3-36 23—22 14 22-49 3-43 22—21 20 21-35 4-69 21—20 29 20-50 4-47 20—19 23 19-52 4-88 19—18 22 18-59 4-57 18—17 20 17-50 5-9 17—16 32 16-58 6-02 16—15 22 15-57 6-48 ( 8 14-53 4-35 16—14 2 13-42 6-45 I 1 12-87 2-0 * Except Nos. 167, 169 and 175, with respect to which see footnote on p. 63, and No. 309, an analysis of an unnamed seam, which appears to be abnormal. 80 THE COALS OF SOUTH WALES. By this combination of tlie analyses the effect of exceptional specimens is partly eliminated and an approximation to the true average percentage of ash is obtained, more or less close according to the number of analyses available. It will be seen that the line of means forms a fairly steady gradient from 1 per cent, at the anthracitic end, to more than 6 per cent, near the bituminous end of the scale. The column 15-14 shows a departure from the gradient, but this is partly due to one analysis (No. 123), in which the ash is exceptionally low, and partly to there being insufficient analyses available to yield a true average. Were more analyses available, the gradient would probably be still further smoothed, but even as it stands it furnishes good proof of the general rule that the percentage of ash increases with that of the bituminous constituent. In connection with this may be taken the fact that anthra- citic coals are more often " solid " than the bituminous seams. Figures for an exact comparison are not easy to obtain, but probably the comparison of a large number of average sections of seams in the two ends of the coal-field would show that the bituminous coals are more apt to be split up by partings of sedimentary material than the anthracitic. Freedona from partings and, to the eye, an almost pejrfect homogeneity are familiar characters in anthracitic seams. The seams them- selves also are probably on the average rather thinner. In order to ascertain wTiat percentage of ash is contained in a mass of miscellaneous plants, and what is the nature of the alteration effected by spontaneous heat, two samples of meadow- hay from the same rick were obtained through the kindness of Messrs. Dumbelton, the one coming from near the outside, where comparatively little heating had gone on, the other from the centre of the rick, where the hay had, been much heated and had become almost black. As the difference in moisture in the two samples were considerable, both were dried at 105° C. before analysis. The analyses were carried out exactly as for a coal, and the results obtained were : — Hay affected by Spontaneous Heat. ProxiTnate Analysis. as residue Ultimate i Light (outside) sample. Dark (heated) sample. Volatile matter .. Fixed oarbonaceo Ash 76-69 15-70 7-61 .nalysis. 69-41 21-31 9-28 Carbon ... Hydrogen Oxj'gen ... Nitrogen ... Ash 45-23 5-85 39-18 2-13 7-61 46-82 5-33 36-75 1-82 9-28 OEIGIN OF ANTHRACITE. 81 or calculated on "ash-free" sample: — Proximate Analysis. Volatile matter Fixed carbonaceous residue Light (outside) sample. 83 00 17 00 Dark (heated) sample. 76-51 23-49 Ultimate Analysis. Carbon .. Hydrogen Oxygen .. Nitrogen ., 48-96 6-33 42-41 2-30 51-61 5-88 40-60 201 It will be noted that the percentage of ash in the light (out- side) sample is 7-61 and in the dark (heated) sample 9-28. Presumably the greater part of this ash was contained in the plants. Further, the net result of the alteration by heating was to diminish the percentage of hydrogen, oxygen, and nitrogen, and thereby increase the percentage of carbon and ash. The foregoing statements may be summed up as follows : — 1. The seams are not all similarly anthraoitic, and though each seam is generally more anthracitic than the one above it, there are many exceptions to this rule. 2. The anthracitic character was not due to faults, but existed before the faults were formed. 3. The anthracite existed as such before the coal-field was reduced by denudation to its present dimensions. 4. The percentage of ash diminishes 'pari passu with the decrease of bituminous matter. These conclusions point to the variations in the compositions of the coals having been either original or at least of very early date. For the disturbances of the strata and the denudation which brought the coal-field to its present shape, were both in the main accomplished before Triassic times. The differences between the coals therefore already existed before any of the Secondary Eocks were laid down. Further than this the evidence derived from the distribution of anthracite does not carry us, but the remaining arguments point to the date of anthracitisation having been contemporaneous with the deposi- tion of the Coal Measures — the strongest being that which is derived from the variation in the percentage of ash, for it is obvious that the variation cannot be due to subsequent altera- tion. A further argument may be derived from the existence of pebbles or fragments of coal in some of the conglomeratic bands which occur not infrequently in the Pennant Grit of South Wales and in other coal-fields. As pointed out by M. Eenault,* these coal-fragments are enclosed in bands of sandstone or argillaceous sandstone. They sometimes have the fracture of ordinary coal, with alternate bright and dull layers, and are * ' Sur quelques Micro-organismes de Combustibles Fossiles,' Bull, de la Soc. de I'Industrie Minerale, s6r. 3, t. xii, 1899, and t. xiv, 1900. Also separately published. 82 THE COALS OF SOUTH WALES. angular; or again, some have been rounded into true pebbles. They have not been deformed by the pressure of the sandstone which envelops them, nor have they shrunk since they were enveloped. It is to be inferred, therefore, that they were derived from some pre-existing coal-seam, and had already acquired their hardness and definite volume when they were buried in the sand — that is to say, they had passed in.to the condition of coal while the Coal Measures were still in process of deposition. In seeking to account for an original difference in the com- position of coals, it seemed worth while to inquire whether there was any connection between it and the distribution of the Coal Measures before they were curtailed by denudation. In parts of Pembrokeshire the original margin of the Coal Measures is recognisable, and though it has been removed by denudation elsewhere in South Wales, there is suificient evidence to enable us to sketch its position approximately. The evidence commences in the Lower Carboniferous rocks. The limestone-series is well developed in South Pembrokeshire, but dwindles awaj-^ rapidly and is actually overlapped by Mill- stone Grit towards the north. Throughout the main coal-field the northward attenuation is no less marked, as is proved not only by a comparison of the relative thicknesses on the north and south crops, but by the poor development in the outlier of Pen Cerig-calch. Lastly, at the north-east corner of the coal- field, the whole limestone-series does not exceed 100 feet in thickness, as compared with about 500 feet further south, the upper zones having been overlapped. Traced in an east-and- west direction the thicknesses are relatively more constant, with a general tendency, however, towards expansion in the south-westerly region of the coal-field. Assuming that the northward attenuation and overlap con- tinued in the tract from which theXower Carboniferous rocks have been denuded, the original margin of those rocks must have lain not far away from, and appears to have run approxi- mately parallel to, the present margin of the coal-field. That the land-mass thus indicated in Central Wales in Carboniferous times extended across St. George's Channel into Wicklow and Wexford is highly probable, but less capable of proof, nor is there in that part of Ireland any evidence left of the overlap of the Lower by the Upper Carboniferous rocks. The position of the original margin of the Coal Measures is more problematical, for by analogy with Pembrokeshire and other regions they may be assumed to have overlapped all the older Carboniferous rocks, and to have extended still farther north. Moreover, their margin probably occupied positions successively farther north as the subsidence which led to the deposition of so huge a mass of sediment progressed. The reasoning, however, which has been applied in the case of the underlying rocks gives a somewhat similar result. The varying thicknesses of the Lower Coal Series, which alone of the subdivisions of the Coal Measures has a sufficiently wide distribution for our present purpose, is shown in Plate 10. The Lower Coal Series extends from the Ifo. 2 Rhondda Seam ORIGIN OF ANTHRACITE. 83 (or its equivalents) down to the Farewell Rock or top of the Millstone Grit. Most of the measurements are taken from shaft-sections published in Vert. Sects, of the Geological Survey, Sheets 80, 81, 83, 84, and 85. But few, if any, of the shafts have reached the Farewell Rock, and several have not been carried down to the lowest coals ; in such cases an addition has been made for the estimated thickness of the unproved strata. The smallest development is found at the east end of the coal-field, where the Lower Coal Series is 625 feet thick. The maximum increase takes place thence in a direction rather north of west, a thickness of 1,710 feet and 1,747 feet being reached in a distance of 12 miles. In the next 4 or 5 miles, however, there is a considerable drop, for in the Rhondda valleys the thickness averages about 1,430 feet. West of these valleys expansion sets in again and continues to the end of the coal- field. The expansion, however, is more rapid along the South Crop than along the North Crop, so that a considerable difference between the two sides of the coal-field develops westward. The greater thickness of the measures of the South Crop is partly illustrated in Plate 2, in which Sections 3, 4, and 7 represent the North Crop, while Sections 2, 5, and 6 represent the South Crop. The direction of maximum thickening is somewhat west of south in the western part of the coal-field as compared with somewhat north of west in the eastern part. Assuming as before that attenuation marks an approach to an original shore-line, this map suggests that the original margin of the Coal Measures also may have been roughly parallel to the present margin of the coal-field, but that it curved south- wards at the eastern end. There appears to have been an area of least subsidence somewhere to the east of the coal-field, pos- sibly in the neighbourhood of the post-Carboniferous anticline which brings up Silurian rocks in the Usk inlier. A comparison of this map with the charts showing the iso- anthracitic lines lends no support to the suggestion that the distribution of anthracite had a direct and constant relation to the position of the shore-line. It is true that in the western end of the coal-field the anthracitic character increases as the thickness of measures decreases, and again in the eastern end the group of seams illustrated on Plate 5 lose bituminous matter towards the region where the measures are thinnest. But, on the other hand it is obvious that the anthracitic area is far from coinciding with the region of smallest thickness of sediments. On the contrary, the smallest thickness in the south-east and the greatest thickness in the south-west are both associated with bituminous coals. Moreover, it is not the case in other parts of the kingdom that anthracite is associated with marginal deposits. South Stafford- shire and the Forest of Wyre being notable examples. It appears, therefore, that though the anthracitic regions of South Wales and Ireland may have been nearer the original margin than much of the bituminous region, that circumstance did not necessarily lead to a difference in the coals. 84 THE COALS OF SOTJTH WALES. But it must be remembered tbat coals vary in cbaracter botb according to the kind of vegetable remains, and according to the parts of the plants of which they are formed. That, again, the preservation of the vegetable mass varied according to the local circumstances, such as the distance it was drifted, the depth of water in which it was submerged, the length of time that elapsed before it was buried, and the nature of the sedi- ment which covered it.* Not only do neighbouring veins show variations due to one or other of these causes, but even parts of the same vein may differ considerably. As an extreme case, the band of cannel which is associated with the 'No. 3 Ehondda Seam may be mentioned. t It is a fact, moreover, that most coals consist of laminae of different appearance, the two kinds most commonly distin- guished being 'dull coal' and 'bright coal.' Though it has not been shown, so far as we are aware, that any bitu- minous coal contains laminae of true anthracite, it is certain that the dull and bright coal diiJer in the amount of bituminous matter they contain, and further, it is often easy to see that the dull coal is formed of fragmentary flattened stems and largely of bark, while the bright coal seldom shows organic structure. With a view to ascertaining the difference in composition of dull and bright lamina? in a Welsh coal, a block of the Three Quarter Seam of Monmouthshire was split along some characteristic dull layers. The dull material was scraped off and readily reduced to a powder not unlike charcoal. + Another portion consisting wholly of bright coal was taken from the same block. The dull powder and the bright portion were then analysed with the following result : — Proximate Analyses of Dull and Bright Layers frovi the Same Block of the Three Quarter Seam. DuU Powder. Bright Coal. Moisture ... Volatile Matter Fixed carbonaceous residue Ash Fuel ratio 1-68 14-71 77-17 6-44 5-24 1-75 31-63 63-96 2-66 2-02 * On these points reference should be made to the exhaustive researches on the origin of coal contained in the following works : — Grand 'Eury F.C., ' Flore Carbonifere du D6partement de la Loire et du Centre de la France,' Paris, 1877. Fayol, H., and others, ' Etudes sur le terrain houUler du Commentry,' Soc. de I'lndustrie minerale, St. Eiienne, 1887-93, Renault, B., ' Sur quelques Micro-organisnies de Combustible Fossiles ib. 1899-1900, and separately published. Barrois, C, ' Le Mode de Formation de la HouiUe,' Ann. 8oc. Geol. du Nord, t. xxxiii., 1904. De Lapparent, A., ' Traits de GAologie,' Ed. 5, 1906, pp. 976-990. Potoni6, H., ' Die Entstehmig der Steinkohle,' Berlin, Ed. 4, 1907. t ' The Country around Pontypridd and Maesteg ' (Metn. Oeol. Survey), 1903, p. 43, &o. J Dull coal has been described as 'Mineral Charcoal.' See analyses given in ' Coal, its History and Uses,' by Professors Green, MiaU, Thorpe,' Riioker and Marshall. 8vo., London, 1878. ORIGIN OF ANTHRACITE. 85 The smaller proportion of volatile matter and the larger pro- portion, of ash in the coal which is demonstrably formed of stems and bark is significant. In these variations . between laminae in the same seam, as well as in the variations between one seam and another, we see differences that can only be due to original deposition. It would be anticipated that both the assemblage of plants and the conditions under which their remains were distributed would be different in the neighbourhood of dry land and in the more central parts of the coal-swamps. Generally the utmost sluggishness is evidenced in the movements of the water in which coal-seams were laid down. A certain sequence is often observable in the associated strata ; sandstone, sometimes conglomeratic, is followed by shale, shale by clay, clay by coal. Each recurrence of this sequence, which may be repeated almost indefinitely, points to a gradual decrease of strength of current from that which could spread abroad sand and pebbles to the almost perfect stagnation in which plant-remains could settle to the bottom. With the slightest movement of the water the plant-remains would themselves be carried distances varying according to the time they took to settle, and would thus be sorted. Such slight movements might be expected near the margins of coal-swamps, where water was being shed off the land. What exactly were the conditions in the physical geography, either in South Wales or in Ireland, which led to a differentia- tion in the material of the coal-seams there is not sufficient evidence to show. But it is a highly significant fact that in South Wales the conditions were maintained during the forma- tion of a succession of coal-seams. As the coast-line retreated northwards, the area of anthracitic coal shifted and kept pace with it, and it is for this reason that the rule generally holds good that each seam in any one locality is less anthracitic than its predecessors. The same rule holds in the coal-field of the Pas de Calais, where it is known as the Loi de Hilt. There it is attributed to metamorphism subsequent to deposition, but it would appear from the facts detailed above that it is a neces- sary accompaniment of the formation of anthracite at successive intervals at a more or less constant distance from a retreating shore-line. While, however, giving due weight to the evidence that the anthracitic character of the coals in part of South Wales is due to original conditions of deposition, we do not lose sight of the changes to which coals are liable in the process of time. It is a general rule that, other things being equal, coals associated with older formations approximate more closely to the anthracitic condition than those of later date. The rule is subject to many exceptions, for coal is peculiarly sensitive to local circumstances, such as intrusion of igneous material or regional metamor- phism, nor can it be asserted that the dislocation of strata, and the thickness and nature of the superimposed material produce no effect. The older the formation the greater is the chance of it having undergone one or other of these vicissitudes, while, apart from this, the lapse of time alone tends to effect changes 86 THE CCALS OF SOUTH WALES. in the character. So far as regards South Wales, it might be argued that the general rule that the older seams are the more anthracitic is due in part to one of these causes, namely, the fact that they were more deeply buried and exposed to a higher temperature than the newer seams. There is, however, no evidence that the coals in the synclines in South Wales are more anthracitic than those in the anticlines, though the difference in level sometimes amounts to several thousand feet. It would apparently be easy to over-estimate the effect due to this cause. Of all the suggested causes of alteration subsequent to deposi- tion, none appear to have been adequate to produce more than a slight modification of the differences due to original com- position. 8^ INDEX. Aberaman, 16, 18. Aberavan, 4, 5. Abercarn, 14, 20. Abercraf, 14, 16, 24. Aberdare, 14, 18 ; group of veins, 67, 68. Alix, M. J., 40. Alteration of coal, 73, 74, 85, 86; by whin-sill, 41, 75. Alumina in ash of plants, 78. Ammanford, 26. Analyses, 13-30 ; methods of, 6-12 ; accuracy of, 33-45. Anthracite, distribution of, 1, 2 ; efiect of storing on, 42-45 ; later appearance of in newer seams, 2, 61-57, 67-69, 73, 86; defined, 59- 64 ; carbon-hydrogen factor of, 63, 64; origin of, 73-86. Ash, determination of, 7, 38-41 ; diminution of in anthracite, 74, 77-80; in meadow-hay, 80, 81. Atkinson, Messrs. M. W. and J., 8. Attix, Mr. J. C, 7. B. Barrois, Dr. C, 84. Barrow, Mr. J., 3. Bay, M. I., 40. Bedwas Vein, 70, 71 ; analysis of, 18. Bevan, Dr. J. P., 73. Big Vein (Carmarthenshire), 52, 54, 55; analyses of, 22, 24, 28, 30. Big Vein (Monmouthshire), 47, 49, 52-54, 67; analyses of, 14, 20. Big Vein (Swansea Vale and Cwm- amman), 4, 48, 49, 61-55, 66, 67; analyses of, 14, 16, 22, 24, 28. Binea Vein, analysis of, 20. Birchgrove, 20. Bischofi, Prof. G., 45. Bituminous coal, defined, 1, 69-64. Bituminous matter, decrease of in older seams, 2, 51-67, 67-69, 73, 85 ; decrease north-westwards, 1, 2, 66-72. Black Vein (Monmouthshire), 47, 51, 54, 66; analyses of, 14, 16, 24, 26, 28. Blaenant Vein, analysis of, 28. Blaenavon, 67. Blaencaegurwen, 24. Blaen Rhondda, 18, 20. Blaenserchan, 16. Blaina, 14, 16, 18. Bodwr {or Bodor) Vein, 64, 70 ; analysis of, 20. Bonville's Court Colliery, 24, 26. Box Big Vein, 5, 71 ; analysis of, 24. Bramwell, Mr. H., 3. BranfiU, Mr. C. A., 22-24. Braslyd Vein, analysis of, 30. Brass Vein, 48, 50, 53, 65, 66, 69; analyses of, 16, 28. ' Bright Coal,' analysis of, 84. Brithdir Vein, 69 ; analyses of, 24, 26. Bronbil, 16, 69. Brynddewey Vein, analysis of, 20. Brynhenllys, 22. Bunning, Mr. T. W., 42. Burns, Mr. D., 74, 77. Bute Pit, 14. Cadoxton Vein, analysis of, 20. Cae David Vein, 53 ; analyses of, 22, 26. Cae Pontbren, 24. Caerbryn, 24. Caking power, determination of, 11. Calorific values, 31, 32. Cannel, 61, 84. Carbonaceous genus defined, 59, 63, 64. Carbon, estimation of, 9. Carbonates in coal, 34, 40, 41, 45. Carbon-hydrogen ratio, 13-31, 62, 65. Carboniferous Limestone, overlapped, 82. Carway Big Vein, 66 ; analysis of, 24. Cawdor, 22, 68. Celynen Colliery, 24. Charcoal Vein, 51, 57 ; analyses of, 20, 30. Church, Prof. A. H., 78. Classification of coals, 1, 58-64, 74. Clyndu Vein, analysis of, 18. Clyne Valley Colliery, 24, 26. Clynhebog Vein, analysis of, 22. Coal-pebbles, 81, 82. Coking by whin-sills, 74,75. Collection, methods of, 3. Colliery Guardian Company, 2, 13- 26. Combustion, method of, 9-11. Cornish Vein, 54, 68, 70; analysis of, 16. Cribbwr Vein, 53, 65, 66 ; analyses of, 14, 16. Curly Vein, 54, 70 ; analysis of, 20. Index. Cwm Bran, 5. Cwm Clic, 16, 20, 68. Cwm Gors, 22. Cwm-llynfell, 16. Cwrt-y-bettws, 20. Four Foot Vein (Swansea), 5, 55, 71; analyses of, 18, 24, 28. Four Foot Vein (Ystradgynlais), 51, 55, 68 ; analysis of, 16. Fuel-ratio, 13-24, 60, 62. De la Beche, Sir H. T., 2, 13-20, 73, 75. De Lapparent, M. A., 84. Denudation subsequent to anthra- citisation, 76, 77. Depth not a cause of anthracitisa- tion, 77, 83. Deterioration of coal, 42-45. Dillwyn Colliery, 20, 22, 68. Disturbances of strata, 73, 75, 76, 81. Dowlais, 14, 18, 66. Drap Vein, 54, 69 ; analysis of, 22. Duffryn Vein, see Dyffryn. Dulais Valley, 68. Dumbelton, Messrs., 80. Dunraven, 18, 20, 22. Dyffryn Vein (Aberdare), 51 ; ana- lysis of, 18; (Llynfi Valley) 53; analysis of, 22. E. Ebbw Vale, 18, 67. Eighteen Foot Vein, 54, 68 ; analysis of, 24, 30. Filed Vein, 52, 67. Ell Vein, analysis of, 18. Emlyn Colliery, 24. Evens, Mr. T., 2. Faults, effect of on anthracitisation, 76, 81. Fayol, Mr. H., 84. Fermentation, effect of, 73. Ferrous compounds, effect of on analysis, 39, 40, 45. Ffaldau, 18. Fiery Vein, 71 ; analysis of, 20. Fischer, Prof. F., 42. Five Foot Vein, 53, 55, 71, 72 ; ana- lyses of, 18, 22, 24, 28. ' Fixed carbonaceous residue,' esti- mation of, 7, 62. Fleck, Prof. H., 42. Forest Vein, 53, 56 ; analysis of, 24, 26. Forster Brown, Mr. T., 3. Four Foot Vein (Aberdare Series), 61, 56, 67; analyses of, 18, 28. Four Foot Vein (Gower), 48, 52, 65, 66; analyses of, 14, 16, 26. Four Foot Vein (Morfa), 53, 65; analysis of, 16. Gadley Four Foot Vein, 51 ; analysis of, 18. Galloway, Prof. W., 74. Garnant, 12, 24. Garw Valley, 68 Geikie, Sir A., 3. Geinitz, Prof. H. B., 42. Germiston, 37. ■ Gilfaoh, 22. Glan Mwrwg Colliery, 24. Glyncastle Colliery, 18. Glyn Colliery, 24. Glyn Corwg, 16, 70. Glyn Neath, 14, 68. Gnapiog Vein, analysis of, 28. Golden Vein, 55; analysis of, 28. Government Laboratory, 9, 12, 13, 26-29, 31, 32. Gower, 70, 76. Graigola Merthyr Colliery, 18. Graigola Vein, 5, 48, 53, 54, 71; analyses of, 18, 20. Graig Vein, 51, 52, 70; analysis of, 20. Grand' Eury, M. F. C, 84. Graphite, 60, 61. Gras-uchaf Vein, analysis of, 22. Green, Prof. A. H., 84. Green Vein, 54, 69 ; analyses of, 22, 24, 28. ' Gross Coal Index,' 61. Grout, Prof. P. F., 58, 61. Gwauncaegurwen, 22. Gwaunclawdd, 14, 16. Gwendraeth-fawr, 1. Hardman, Mr. E. T., 74. Hart, Mr. F., 43. Hartig, Prof. E., 42. Hedley's Vein, analysis of, 20. Hill's Pit, 24. Hill's Plymouth Merthyr Colliery,- Hirwain, 14, 66. Hollinger, Dr. M., 8. Hood, Mr. A., 2. Hook, 24, 67. Horn Vein, analysis of, 14. Hugh^ Vein, 54, 70, 71; analysis Hydrogen, estimation of, 9, 34 41 Hydrous minerals, effect of in ana- lysis, 41, 45. .INDEX. 83 'Inert Volatile,' 60-62. International Colliery, 24. ' Intrinsic Value ' of Coal, 01. Ireland, anthracite in, 75. Iso-anthracitic charts, explained, 65-72. John, C. von, 41. Johnston, Mr., 37. Jones Price, Mr. T., Jordan, Mr. H. K., Joseph, Mr. T., 74. K, Kilburn coal (Leicestershire), 34-38. Kilgetty Vein, analysis of, 24. L. Lantern Vein, analysis of, 26. Leland, 1. Lignitious coal, 59-61 Little (Brass) Vein, 48, 56 ; analyses of, 16, 26. Llanelly, 1, 5, 20. Llangyfelach, 18 Llanhilleth, 14. Llanmorlais, 16. Llantwit No. 3 Vein, 5. Llynfi, 14, 22, 26, 66, 68. ' Loi de Hilt,' 85. Loughor Fiery Vein, analysis of, 20. Lower Coal Series, thicknesses of, 82, 83. Lower Four Foot Vein, analysis of, 16. Lower Level Vein, 65 ; analyses of, 24, 26. Lower New Vein, analysis of, 26. Lower Pumpquart Vein, 54-57, 65, 66; analyses of, 22, 30. Lower Triquart Vein, 54, 55, 65, 66 ; analysis of, 22. Lower Vein, 52, 65, 66 ; analyses of, 22, 28. Lower (Welsh) Vein, 68; analysis of, 20. Lunge, Prof. G., 9. Lynch Vein, analysis of, 24. Meade, Mr. R. K. 7. Meadow-hay, analyses of, 80, 81. Meadow Vein, 53, 66, 66 ; analysis of, 16. Melly, Mr. E. F., 77. Meta-bituminous coal, 59, 64. Meta-lignitious coal, 64. Metamorphic theories of anthracite, 73-77, 85, 86. Miall, Prof. L. C, 84. Middle Vein, 52, 65, 66; analyses of, 14, 22, 28. ' Mineral charcoal,' analysis of, 84. Moisture, estiination of, 6, 7 ; effect of in analyses, 33-38 ; effect in stored coal, 42. Morfa, 14, 16, 66, 69. Muck, Prof. F. 33. Mushet, Mr. D., 73, 77. Mynydd Black Vein, analysis of, 16. Mynyddislwyn Vein, 5, 70, 71 ; ana- lyses of, 18, 24, 26 ; after storing, 44. Mynydd Newydd, 18, 20 N. Nantyglo, 16, 18. Neath, 20. New Cross Hands Vein, analysis of, 22. Nine Foot Vein (Aberdare Series), 4, 49-51, 53, 56, 66,. 67, 69; analyses of, 14, 26, 28, 30; after storing, 43. Nine Foot Vein (Morfa), 53; analysis of, 14. Nine Foot Vein (Ystradgynlais), 54, 56 ; analysis of, 14 ; after storing, 43. Nitrogen, estimation of, 9. Ogmore Valley, 68. Old Castle Colliery, 20, 71. Old Coal, 51, 62, 65, 66; analysis of, 16. Onllwyn Colliery, 24. Ortho-anthracite, 63. Ortho-bituminous coal, 59, 64. Ortho-lignitious coal, 64. Oxygen, estimation of, 39-41. P. M. Machen, 16. Marginal deposits, 82, 83, 85. Marshall, Prof., 84. Martin, Mr. H. W., 2. Para-bituminous coal, 59, 64. Park and Blaina Colliery, 16. Parr, Prof. S. W., 58, 60. Pas de Calais, 85. Peacock Vein, 48, 50, 51-56, 65; analyses of, 16, 20, 24, 28. 90 iNDE5Ci Peat, '60, 61. Pebbles of coal, 81, 82. Pembrokeshire, 1, 2, 66, 76, 82. Penlan Vein, analysis of, 16. Penrhiw, 20, 24, 70. Pen-y-filia Vein, 63 ; analysis of, 18. Pen-y-graig Vein, 69 ; analysis of, 16. Per-bituminous coal, 59, 64. Percy, Dr. J., 2, 13-27, 42, 45, 68, 77. Playfair, Dr. Lyon, 2, 13-27. Pontardulais, 71. Pontyberem, 14, 22. Pontyberem No. 1 Vein, analysis of, 22. Pontypool, 5, 67. Potoni6, Prof. H., 84. Primrose Colliery, 16, 18. Proximate analysis, 7 ; defects of, 33, 34. Pseudo-anthracite, 59, 63. Pseudo-bituminous coal, 64. Pumpquart Vein, analyses of, 24, 28 PwUbach, 20. Pwllfaron, 14, 16, 24. Pyrites, effect of in analysis, 39-41, 45. Eas-las Vein, 47, 48, 52, 66, 69, 78 ; analyses of, 14, 26. Red Ash Vein, 69 ; analysis of, 24. Red Vein (Monmouthshire), 51, 56; analyses of, 20, 26, 28. Red Vein (Ystradgynlais), 49, 53- 55, 68, 70 ; analyses of, 20, 22, 28, 30. Renault, M. B., 60, 81, 84. Reynalton Colliery, 26. Rhondda No. 3 Vein, 58, 56, 70, 84 ; analyses of, 20, 26. Rhondda No. 2 Vein, 2, 4, 48, 51, 56, 69, 70 ; analyses of, 16, 26, 28. Richardson, Mr. J., 77. Richters, Prof E., 42, 45. ' Ring Coal,' 1. Roberts, Mr. J., 3, 74. Rock-fawr Vein, 48, 69 ; analyses of, 16, 26. Rock Vein (Carmarthenshire), analysis of, 30. Rock Vein (Pembrokeshire), analysis of, 28. Rock Vein (Pontypool), see Ras-las Vein. Rock Vein (Machen), analysis of, 16. Rotten (Bodwr) Vein, 54, 70; analysis of, 20. Riicker, Prof. A. W., 84. Sampling of coal, 6. Scottish coal, 34-38. Semi-anthracite, 60, 61, 63, 77. Semi-bituminous coal, 59-61, 64, 65, 77. Sequence of seams, 4. Seyler, Mr. C. A., 2, 11, 13-31, 58- 60, 62-64, 74. Six Foot Vein (Aberdare Series), 53, 56, 67 ; analyses of, 18, 22, 26, 28. Six Foot (Graigola) Vein, 5, 48, 63, 54, 71 ; analyses of, 18, 20. Six Foot Vein (Llanmorlais), analysis of, 16. Slatog Vein, 54, 70 ; analysis of, 20. ' Slip-cleavage,' 74, 75. South Staffordshire compared, 83 ; Thick Coal, 34-38. South Wales Institute of Engineers, Specific Gravity, estimation of, 6, 11, 12. Spontaneous combustion, 42. Stanllyd Vein, 4, 49, 52, 65, 66, 67 ; analyses of, 14, 16, 24, 28, 30. Steam Coal, 4 ; analysis after stor- ing, 43. Stewart, Mr. W., 3. ' Stone-coal,' 1. Stwrain Vein, 68. Sub-bituminous coal, 59. Sulphur in coal, estimation of, 8; effect of in analysis, 38-40, 77. Swansea Five Foot Vein, 53, 55, 71, 72 ; analyses of, 18, 22, 24. Swansea Four Foot Vein, 55, 71 ; analyses of, 18, 24. Swansea Six Foot Vein. See Six Foot (Graigola) Vein. Swansea Three Foot Vein, 63, 71; analysis of, 20. Swansea Vale, 71. Tallis, Mr. Fox, 3. Temperature, effect of, 73-75, 85, 86. Thickness of measures, 5, 74, 82, 83. Thorpe, Prof. T. E., 84. Three-foot-one Vein, analysis of, 30. Three Foot Vein (Clyne Valley), 65, 66; analysis of, 24. Three Foot Vein (Swansea). See Swansea. Three-quarter Rock Vein, analysis of, 18. Three-quarter Vein, 48, 51-64, 67; analyses of, 18, 24. Tillery Vein, 4, 69 ; analyses of, 24, INDEX. 91 Timber Vein, 65-67 ; analysis of, 24. Tirpentwys, 14, 20, 24. Trap rocks, 73, 75. Tregloin (Trigloin) Vein, 49, 55, 65, 66 ; analysis of, 20. Triquart Vein, analyses of, 30, 55. Two-foot-nine Seam, 51, 52, 67, 68; analyses of, 18, 26, 28. Ty-chwyth, 22. U. Ultimate analysis, 9, 34-45. Upper Four Foot Vein, 52, 67, 71 ; analysis of, 18. Upper (or Pen-y-graig) Vein, 69; analysis of, 16. V. Vale of Neath, 68-70; Disturbance, 76. Variations in seams, 46-50. Varteg, 14, 18. Ventilation of coal, 42. Victoria Vein, analysis of, 26. Vobster, 73. Volatile matter, estimation of, 6, 7 ; afiected by moisture, 33-38. W. Ward's Fiery Vein, 54, 71 ; analysis of, 20. Weigfawr, 20. Welsh Vein, 69; analysis of, 20. Wernddu Vein, analysis of, 26. Wernfiraith Vein, 5, 53, 71; analysis of, 16. Werntarw Vein, analysis of, 28. Whin-sill, effect of on coal, 41. Wight, Mr. W. D., 2. Wood, 60, 61. Wyre Forest, 83. Y. Yankee Vein, 52, 65 ; analysis of, 24. Yard Vein (Aberaman), analysis of, 16. Yard Vein (Carmarthenshire), analysis of, 28. Yard Vein (Clyne Colliery), 52; analysis of, 24. Yard Vein (Llynfi), 53 ; analysis of, 22. Ynyscedwyn, 14, 22. Ynysyfaio, 18. Ynysygeinon, 22. Ynysymond, 20. Ystradgynlais, 16, 24. Missing Page SIX INCH MAPS ON THE SCALE OF 6 INCHES=1 MILE. (1 to 10560). The six-inch maps within which any part of the coal-field is indnded «re being published. The following can be bought uncoloured, price 1*. 6d. each quarter-sheet, or hand-coloured (either Drift or Solid) at the cost of colouring ; the remainder are in preparation : — Brecknock : — 43 NW (Glam. 3 NW ; Carm. 50 NW), 43 NE, 43 SW (Glam. 3 SW, Carm. 50 SW), 43 SE (Glam. 3 SB) ; 44 NW, 44 NE, 44 SW (Glam. 4 SW), 44 SE (Glam. 4 SE) ; 46 SW (Glam. 6 SW) ; 47 NW (Mon. 11 NW), 47 NE (Mon. 11 NE) ; 48 NW (Mon. 12 NW) ; 49 NE (Glam. 10 NE) ; 50 NW;jGlam. 11 NW), 50 NE (Glam. 11 NE) ; 51 NW (Glam. 12 NW). Carmarthen : — 41 SE ; 47 NW, NE, SW, 47. SE ; 48 NW, NE, SW, 48 SE (Glam. 1 SE) ; 49 NW (Glam. 2 NW), 49 NE (Glam. 2 NE), 49 SW (Glam. 2 SW), 49 SE (Glam. 2 SE) ; 50 NW (Breck. 43 NW, Glam. 3 NW), 60 SW (Breck. 43 SW, Glam. 3 SW) ; 53 NE, SE; 54 NW, NE, 54 SW, 54 SE ; 55 NW (Glam. 7 NW), 55 NE (Glam. 7 NE), 55 SW (Glam.' 7 SW) ; 57 NW, 57 NE (Glam. 21a NE), 57 SE (Glam. 21^ SE) ; 58 NW (Glam. 22' NW), 58 NE, 58 SE (Glam. 22* SE) : 59 NW (Glam. 14 NW), ' 59 SW (Glam. 14 SW). Glamorgan : — 1 SE (Carm. 48 SE) ; 2 NW (Carm. 49 NW), 2 NE (Carm. 49 NE), 2 SW (Carm. 49 SW),, 2 SE (Carm. 49 SE) ; 3 NW (Breck. 43 NW, Carm. 50 NW), 3 SW (Breck. 43 SW, Carm. 50 SW), 3 SE (Breck. 43 SE) ; 4 SW (Breck. 44 SW), 4 SE (Breck. 44 SE) ; 6 SW (Breck. 46 SW), 6 SE (Mon. 10 SE); 7 NW (Carm. 55 NW), 7 NE (Carm. 55 NE),7 SW (Carm. 55 SW), 7 SE ; 8 NW, NE, SW, SE ; 9 NW, NE, SW, SE ; 10 NW, 10 NE (Breck. 49 NE), 10 SW, SE ; 11 NW (Breck. 60 NW), 11 NE (Breck. 50 NE), 11 SW, SE ; 12 NW (Breck. 61 NW), 12 NE (Mon. 16 NE), 12 SW, SE ; 13 NW (Mon. 17 NW), 13 SW (Mon. 17 SW) ; 14 NW, NE, SW, SE ; 15 NW, NE, SW, SE ; 16 NW, NE, SW, SE ; 17 NW, NE, SW, SE ; 18 NW, NE, SW, SE ; 19 NW, NE, SW, SE ; 20 NW (Mon. 22 NW), 20 SW (Mon. 22 SW) ; 21* NE (Carm. 57 NE), 21* SE (Carm. 57 SE) ; 22» SE (Carm. 58 SE), 22* NW (Carm. 68 NW), 22 NE, 22 SE, 23 NW, NE, SW, SE ; 24 NW, NE, SW, SE ; 25 NW, NE, SW, SE ;' 26 NW, NE, SW, SE ; 27 NW, NE, SW, SE; 28 NW, NE, SW, SE ; 29 NW (Mon. 27 NW>^, 29 SW (Mon. 27 SW), 29 SE (Mon. 27 SE) ; 33 NW, NE, SW, SE ; 34 NW, NE, SW, SE ; 35 NW, NE, SW, SE ; 36 NW, NE, SW, SE ; 37 NW, 37 NE (Mon. 32 NE), 37 SW ; 41 NW, NE ; 42 NW. Monmouth : — 10 SE (Glam. 6 SE) ; 11 NW (Breck. 47 NW), 11 NE (Breck. 47 NE), 11 SW, SE ; 12 NW (Breck. 48 NW), 12 SW ; 16 NE (Glam. 12 NE) ; 17 NW (Glam. 13 NW), 17 NE, 17 SW (Glam. 13 SW), 17 SE ; 18 NW, SW, SE ; 22. NW (Glam. 20 NW), 22 NE, 22 SW (Glam. 20 SW), 22 SE ; 23 NW, NE, SW ; 27 NW (Glam. 29 NW)„27 NE, 27 SW (Glam. 29 gW), 27 SE ~ (Glam. 29 SE) ; 28 NW, SW ; 32 NE (Glam. 37 NE). The remaining six-inch maps which are included in the one-inch New Series maps named above, but which do not contain anjrpart of the coal- field, are not published, but MS. copies have been deposited in the