8 Schouten Island. 



The country behind undulates a good deal, and is, 

 therefore, naturally well drained. On the other hand, 

 the thick bed of hard clay with vegetable impressions 

 immediately over the coal is apt to flake off and descend 

 in large irregular masses, and does not on that account 

 form a good roof. 



It would, therefore, in mining be requisite to prop 

 strongly with timber, and to leave ample solid pillars of 

 coal. At the same time, I observe, that it is only in those 

 portions of the galleries in which the coal has been 

 worked completely out that the roof has fallen in ; and 

 that where the roof is well arched in the anthracite and 

 shale in the upper part of the seam, no separation what- 

 ever has occurred. By adopting this practice throughout, 

 timber might therefore, to a great extent, be dispensed 

 with. 



With reference to the insufficiency, however, of these 

 clayey beds as a roof, it is right to state that the passages 

 have all been left open to the action of air and moisture, 

 which could not but lead, in the nature of things, to 

 partial disintegration and detachment of masses from 

 both roof and sides. 



The old workings are of the following nature and 

 extent : — 



One main drift begun a little above high water-mark, 

 and nearly 6 feet x 6 feet, has been carried in the 

 direction (S.S.W. and W.S.W.) or range of the seam 

 more than 100 yards. 



From this two branch galleries have been worked to- 

 wards the crop, so as to communicate round a massive 

 square pillar. 



A narrow air-course had been carried thence to the 

 surface of the bank. 



The main drift has a slight rise inwards, so that when 

 the floor is clear from obstruction, water finds its way to 



