286 



TRANSACTIONS OF THE 



from sixteen to thirty yards square^, according to the 

 dimensions of the seam. 



In these deep galleries the mode of working out the 

 coal is upon the slope or plane, commencing with the top, 

 or as a flight of stairs. The labour is principally per- 

 formed by hired slaves, under competent direction. 

 Mules are employed under ground to draw the wagons 

 to the bottom of the shaft. As the shafts are chiefly 

 sunk in solid rock, curbing is not commonly required 

 beyond the first 50 or 60 feet.* 



Of other useful mineral substances there are few traces 

 in the Richmond basin. 



In the shaft of the Maidenhead mine, 20 feet above 

 the coal was passed through a bed, from six to eighteen 

 inches thick, of very hard bluish-green argillaceous rock, 

 containing some iron. This bed is much intersected by 

 small white veins of carbonate of lime, forming septa, and 

 resembling some of the weaker varieties of argillaceous 

 iron ore. 



Mineral charcoal occasionally prevails in the same 

 mine. 



GENERAL CHARACTER OF THE RICHMOND COAL FIELD. 



The prevailing circumstances which are developed 

 during the subterranean excavations in this remarkable 

 mass of coal, are such as would be expected to attend 

 the deposition of vegetable matter; or of any substance in 

 fact, not altogether in a state of fluidity, yet capable of 

 entering into and filling up the innumerable inequalities 

 and minor cavities of the original granite bed, and at the 



* Price of coals at the pit's mouth, at the head of the railway, twelve and a 

 half cents per bushel of five pecks, weighing ninety pounds. At Richmond 

 eighteen and a half cents; inferior, sixteen cents per bushel. 



Contracts are, I understand, occasionally entered into on more favourable 

 terms. 



Cost of transportation on the thirteen miles of railroad to Richmond, the 

 head of sloop navigation, six cents per bushel. 



