412 The Thick Goal of South Staffordshire. 



ice. These little plates of ice, at times, come tip in such 

 abundance, that when they rise to the surface they resemble 

 smoke, and often increase during their passage up to a diame- 

 ter of more than one line. When the water has reached a 

 half or a whole degree below freezing point, Wilcke observed 

 these same little plates of ice rise to the surface, but they were 

 now encircled by a leafy edge. If water below freezing point 

 which is kept in a glass cylinder, is agitated or shaken hastily, 

 ice began to grow up from the bottom, but not in the upper 

 water where the agitation was greatest. If water below freez- 

 ing point happens to come in contact with a fast body an ice 

 formation in general takes place, and very quickly if this fast 

 body is encrusted with ice. 



THE THICK COAL OF SOUTH STAFFORDSHIRE. 



BY J. JONES, SEC. DUDLEY GEOLOGICAL SOCIETY. 



The coal-field of South Staffordshire and East Worcestershire 

 is, in many respects, of a peculiar character; but it is parti- 

 cularly remarkable in the extent of its mineral treasures. The 

 several seams of coal and clay ironstone of superior quality 

 occur, for the most part, at a short depth below the surface, 

 and hence the general plan of mining procedure is to work 

 only a very limited area by means of each pair of shafts put 

 down. The consequence of this is that the whole of the older 

 and richer portion of the district is studded with coal-pits, 

 either now in operation, or marking the places where the 

 precious minerals have been exhausted. Each mine is sur- 

 rounded by a vast accumulation of rubbish, which has been 

 drawn up chiefly when getting out the particular seam known 

 as the thick or ten-yard coal. The method of working the 

 coal and ironstone in this district is considered by the most 

 competent judges to be exceedingly rude, and wasteful in a 

 high degree ; but it is in the ten-yard seam above mentioned 

 that the greatest recklessness has prevailed, and, indeed, 

 according to recent discussions on this subject, appears to pre- 

 vail at the present time. This immense deposit of fuel is so 

 remarkable in many particulars that it claims the especial 

 attention of geologists ; but just lately, owing to an unfortunate 

 dispute between the colliers and their masters, a very 

 interesting mass of thick coal has been exposed in what is 

 termed an open working. The full dimensions of the seam 

 have been well displayed in a large, trench-like quarry, in a 

 portion of the district where the coal measures crop out to 



