222 



REPORT — 1880. 



' Big Vein ' of the Aman Valley, known as the ' Stanlljd ' of the Gwen- 

 draeth and Mynydd Maur districts, has the highest reputation for purity 

 and strength. This seam must not be confounded with the ' Nine-foot ' 

 vein, to which the appellation of ' Big Vein ' is sometimes applied, both 

 in the Gwendraeth Valley and at Mynydd Maur. 



Another well-known seam is the ' Brass ' vein, known also as the 

 ' Peacock ' and the ' Diamond ' vein, which attains its best condition in 

 the Swansea Valley, and is greatly esteemed for the various purposes to 

 which anthracite is applied. Many of the other seams are also deserving 

 of special notice ; but having given such a description of the coal-field as 

 may lead us, to some extent, to realise its value in respect to its resources 

 and productive power, it will be desirable to consider the difference, 

 chemical and otherwise, that distinguishes pure anthracite from semi- 

 anthracite and bituminous coals ; and here we are necessarily met with 

 the same difficulty as in attempting to define the boundaries of the coal 

 basin, and from the same cause, that of the gradual and almost imper- 

 ceptible merging into each other of the coals referred to. Professor 

 Dawkins says : ' The whole difference between anthracite coal and ordi- 

 nary coal consists in this, that the bituminous portion of the anthracite 

 has been removed in some way ; while in the case of ordinary coal, the 

 hydrogen and oxygen of the bituminous part still remains.' But this 

 definition still leaves us to determine where anthracite ends and bitu- 

 minous begins ; and, in considering this portion of my subject, I have 

 felt myself compelled to fall back upon the analysis I have before me of 

 a few of the coals worked in the South Wales basin, which are recog- 

 nised as examples of the various descriptions referred to. 



PURE ANTHRACITE. 

 Pembrokeshire. 



100-00 



