178 RANIGANJ COAL FIELD. [Pt. II. CHAP. II. 



been given in the margin. It should be remembered that a very con- 

 siderable quantity of both rubble and small coal is sold, so that the 

 gross produce of marketable fuel is considerably greater than that 

 given, probably amounting to about one-fifth to one-sixth more. 



IX. The number of steam engines, whether for pumping, or 

 pumping and drawing, employed at each mine. No engines are used 

 for drawing alone. 



X. The total thickness of the seam of coal on which the workings 

 are carried on. 



XI. The thickness of the portion extracted. 



** 



