170 JtANIGANJ COAL FIELD. [Pt. II. CHAP. II. 



water, and re-worked, after the rains are over, but a new quarry is 

 opened at the side of it, so that the out-crop of many seams of coal 

 is marked by a series of large excavations filled with water. These 

 present, in two ways, serious impediments to deeper workings on the 

 same seam : 1st, if there has been under-cutting, there is a risk of 

 tapping the old workings, for no record of their extent is ever kept ; 

 and, 2nd, the water from the quarries draining through the coal largely 

 increases the quantity in the mine ; this has, in some instances, proved 

 so serious an inconvenience, that it has been found necessary to refill 

 the old quarries with earth. 



There can be no question that the practice of commencing to work 



Working the out-crop. seams of coal h J parries on the out-crop is 

 injurious. altogether injurious to the prospects of the mine. 



The coal is necessarily inferior, and this fact frequently injures seriously 

 the market value of the fuel. It is, however, very cheaply extracted, 

 no expensive machinery being necessary, and only cheap native 

 supervision being required, while the laborers are a class who will 

 not, for the most part, work underground as miners. The dangers 

 of extensive under-ground workings connected with a quarry were, on 

 one occasion, -forcibly illustrated at Mangalpur. The Singaran stream 

 runs past the quarries, one of which was protected by a bank of earth ; 

 a sudden rise of the stream breached this, and the water poured into 

 the mine. About twenty-five miners, who were in the deeper work- 

 ings, were drowned. 



There is much danger of any recollection of the extent to which 



old workings were carried dying out, and as the 

 Necessity for good plans. 



system of regular mining becomes largely in- 

 troduced, the risk of tapping abandoned galleries will be considerable. 

 Even a greater risk, if possible, results from abandoning large mines 

 without careful records of their extent. The number of cases in which 

 this has hitherto occurred is small, and it is most desirable that the 



