ON MECHANICAL AND ECONOMIC PROBLEMS OF THE COAL QUESTION. 615 



passages, and the writer suggests that a very material and possibly suffi- 

 cient reduction of temperature may be looked for even to a depth of 

 4,000 feet, if the present practice in the best modern deep collieries is 

 adopted of not only working the coal ' longwall ' and upon the Midland 

 system of few passages near the face of working, but systematically 

 packing the spaces from which the coal has been excavated, thus reducing 

 the parts of the mine exposed to the currents of air to the lowest practi- 

 cable limit, namely the air passage and simple working faces ; and by 

 carrying the intake airways as direct as possible to the point of working, 

 and making the working face in as straight a line as practicable, it may be 

 possible to reduce the natural temperature of the stratification alongside 

 the air passages at from 3,000 to 4,000 feet in depth in this way by from 

 15° to 25° Fahr. 



Even at this reduced temperature, which would mean over 90° at 

 4,000 feet in depth, labour cannot be applied without considerable difficulty ; 

 but it would be apparently possible at all events to work the best of the 

 seams at this depth at an increased cost. 



Practically, in the absence of any mechanical process for artificially 

 cooling the air at the point where it is required to be used in the working 

 face, the alternative suggested may be effected if the air passages and 

 currents of air are made large enough, and the sides of the passages and 

 the gob or excavated spaces as far as practicable sealed up. 



Before dealing with the second question, namely : What changes in 

 our charges for transit and other items of cost are possibly practicable ? 

 it may be of interest to review shortly the general progress of coal mining 

 in this and other countries at the present day. 



Taking Great Britain to begin with, the cost of working coal has even 

 at the present time under existing conditions a tendency to increase. 

 This is chiefly due to the greater cost of labour and the extra charges for 

 rates and taxes. The first item is undoubtedly increasing, and this is not 

 altogether due to less work being performed by the workmen for a ^iven 

 wage, but partly to the cost of larger staffs and improved appliances to 

 meet the requirements of the various Coal Mines Regulation Acts ; and 

 whilst the precautions required by these Acts undoubtedly have added to 

 the expense of working, they have also resulted in the saving of life, and, 

 therefore, so far as this charge adds to the cost, it is an addition which 

 cannot be a subject of regret to the community. There has also latterly 

 been a gradual tendency to an increase in rates and taxes, which are now 

 a verj' serious impost on coal mining, and, unfortunately, in the mining 

 districts where the coal-owners are the largest ratepayers, they have little 

 or no control over the expenditure of the proceeds of local rates. 



This item of rates and taxes is, in fact, growing \vithout check, and 

 unless something can be done to stop wasteful expenditure, it is likely to 

 be a most serious charge upon coal mining in this country. 



Then again, a further addition to the cost is imminent by reason of the 

 Workmen's Compensation Act. And some increase is also caused by thin 

 seams now being worked in some of the smaller districts where the thick 

 seams have been exhausted. 



Then also some deeper pits have been opened with perhaps a higher 

 average cost, due to depth ; in fact natural causes have begun to operate 

 to a small extent. 



On the other hand, considerable economies have been achieved within 

 the last twenty-five years by using high pressure steam, a better class of 



