MINING PRACTICE. 89 



(2) Dressing. 



The practice of splitting the " books " and dressing the mica sheets 

 at the surface does not lend itself to the criticism which I have been 

 forced to make with regard to the underground work. In Bengal the 

 sheets are merely sickle dressed by trimming off the broken and flawed 

 edges by obliquely directed cuts with a large knife or sickle. The 

 dressed sheets are left quite irregular in shape, and in this form are sent 

 to the London market. A similar practice is adopted in many of the 

 Nellore mines, and many of the managers stated that they have been 

 instructed by London agents to supply the mica in these irregular 

 pieces rather than in rectangles. Mr. E. H. Sargent, however, on 

 opening the Inikurti mines, instituted a practice of sending mica to the 

 market only in the form of the largest possible rectangle, and he 

 claimed that the system was more profitable. Rectangles are utilized 

 with less waste than irregular sheets of the sarne grade, and they 

 consequently bring a higher price, besides being more convenient to 

 pack for safe carriage, and requiring less freight. The writer was for- 

 merly inclined to favour the system of cutting perfect rectangles before 

 placing the mica on the market ; but the advantage is probably not so 

 great since mica of various shapes is required and the trimmings can 

 be turned to account. There is now, however, another and much more 

 important reason for sending mica to the general market in the roughly- 

 trimmed (sickle-dressed) condition, and that is the outcome of a recent 

 change in the import tariff of our largest customer, the United States. 

 According to the Dingley Tariff Act, which came into force on July 24th 

 1897, m > ca imported into the United States was classified into (1) 

 " unmanufactured,' and (2) "cut or trimmed," the former class includ- 

 ing the roughly cleaned or "thumb-trimmed " mica, as they call it in 

 Canada. Both kinds are taxed with an ad valorem duty of 20 per 

 cent. ; but, whilst the " unmanufactured" material is charged with an 

 additional 6 cents per lb., the " cut" mica is taxed with an extra 12 

 cents a pound. The effect of this law soon made itselt manifest in a 

 very natural way on the trade, not decreasing the total import, but 



( 79 ) 



