8o HOLLAND : MICA DEPOSITS OF INDIA. 



working of the many fine pegmatite sheets hitherto undevel- 

 oped. 



The means adopted for ensuring the safety of the mines are, as a 

 rule, most prefunctory, whilst no special effort whatever is made to 

 ventilate the deep, narrow holes in which the miners are crowded, 

 smoky oil-lamps used and explosives largely employed. Whilst present 

 at a mine extended to just 300 feet below the surface, I witnessed 

 the discharge of 25 holes charged with dynamite : the blasts went off 

 in salvoes of twos and threes, and, after a slight discussion at the pit's 

 mouth as to the number of successful fires, the miners streamed into the 

 pit, whilst the fumes and dust from the explosions floated out at the 

 mouth, and ventilation was allowed to proceed by simple diffusion. 

 To a certain extent the ventilation difficulty cures itself by the cessation 

 of work at nights; but the fact that I found it impossible, on account of 

 the haze of smoke and dust, to obtain a photograph, even in strong 

 magnesium light, at a depth of no feet in one of the mines, shows 

 that the ventilation is not above reproach within two hours after the 

 commencement of the day's work. 



In order to reduce the fouling of the air in the mines to a minimum, 

 blasting is generally performed as the last operation in the evening, 

 and the mines are then left for the night. As a consequence of this 

 practice, much of the mica thus freshly exposed is stolen in the night, 

 and the owners have to pay in another way for the false economy of 

 neglecting the recognised principles of mining. 



Notwithstanding the definite regulations framed by the Local Gov- 

 ernment, there was not a single plan of any of the mines in existence 

 when I visited the district in 1898, and the managers knew only 

 in a general way of the positions of the works and miners under 

 ground. The enforcement of this regulation is not only important to 

 meet the questions which might arise in case of accident or trespass, 

 but if plans were regularly made the managers would be able to direct 

 the work in a much more economical and intelligent way than is done 

 at present. A case in the Koderma area will illustrate this point : — A 



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