368 Scientific Proceedings, Royal BuUin Society. 



In connexion with the Eock Colliery, Mr, Joseph Dobbs points 

 out that no batrachian or other fossils, such as have been found in 

 the northern channel, have been there met with ; and he suggests 

 that possibly there might have been two channels in connexion 

 with this One-foot coal — that to the north or the Jarroiv Channel 

 being separated some way or other from the South or Rock and 

 Kilgorey Channel. The measures found in connexion with the coal 

 of the Jarroio Channel, when compared with those found in con- 

 nexion with the coal of the Rock and Kilgorey Channel, may add 

 weight to Mr. Dobbs' suggestion. 



To the northward of the Ooolbaun fault there is a remarkable 

 circumstance connected with the washout, which is, that the present 

 valley of the Dinan river nearly coincides with it. Whether this 

 is a mere accidental coincidence or is due to some natural cause it 

 is hard to determine. 



The accompanying section (PL XIY. fig, 1), with the small 

 section (fig. 2), represent the character of the channel as proved in 

 the Clogh and Jarrow Collieries ; while the old working at Geneva, 

 to the S. E., and the new ones at Massford, to the westward, 

 suggest that in those places also the channel is of a very similar 

 character and width. 



From this section it would appear as if the full channel was, 

 on an average, about 350 yards (1050 feet) wide, while the profit- 

 able coals in its deepest portion were not more than 200 yards 

 (600 feet) wide ; the greatest depth of coal being four feet, which 

 more or less gradually lessened towards the margins, especially the 

 north margin. 



Another peculiarity of the Jarroiv Channel, which does not ap- 

 pear in Meadows' section on account of its small scale, is that, as 

 we proceed towards the edges, especially southward, eastward, and 

 westward, there are breaks or sudden lessenings of the thickness of 

 the profitable coal, locally called " troubles," or " faults." This 

 phenomenon is roughly represented in the sketch (fig. 2). The 

 roof is continuous ; but the floor of the coal rises, and on each rise 

 or " trouble " (at a, a, a) there is only a sort of clayey culm, or 

 buddagh, i. e., a mixture of coaly and clayey or shaly matter ; 

 while at both sides of the " trouble " the coal is found : on the 

 channel side it is usually of the regular thickness, while at the 

 other, or towards the edge of the channel, the coal gradually 



