ON MECHANICAL AND ECONOMIC PROBLEMS OF THE COAL QUESTION. 613 



the continual development of the unopened portions of our coaltields and 

 the resources of good and thick seams still un worked in existing collieries, 

 but after fifty years or so this progress will be much more rapid. 



It will now, therefore, be convenient to consider in what direction it 

 may be practicable to improve our existing appliances for working coal, 

 and otherwise reduce the cost of working deep and thin seams of coal in 

 the future. 



This naturally divides itself into, first, the improvements which may 

 be achieved by the mechanical and mining engineer, and, secondly, what 

 changes in our charges for transit and other items of cost which come 

 more properly within the province of the Economist than the Engineer, 

 are possibly practicable. 



Dealing hrst with the improvements which may be effected by the 

 mechanical and mining engineer, these may be divided into — (a) improve- 

 ments which may be effected equally applicable to existing collieries and 

 future coal mining ; (6) improvements which can be effected applicable 

 especially to the working of coal from great depths. 



Under the head of (a) we have — 



1. Mechanical application of machinery for cutting thin seams' and 

 exceptionally hard thick seams. 



2. Improvements which may be effected in underground haulage. 



1. Coal-cutting Machinery. 

 Machines may be classed as below : — 



(rt) Heading machines. 



(6) Machines adapted for working in headings or ' rooms.' 

 (c) Machines adapted for continuous ' longwall ' faces. 

 {d) Percussive drills mounted on wheels for use in headings, rooms, or 

 ' longwall ' faces. 



2. Improvements which may he effected in Underground Haulage. 



This comprises primary and secondary haulage : primary comprising 

 the haulage between the bottom of the shaft and points upon the haulage 

 roads, within a varying but moderate distance from the working coal face, 

 and secondary haulage being the conveyance of the coal between these 

 points and the working face. The writer sets out the various systems of 

 haulage, and states the cost of primary haulage to be from 2c?. to 4fZ. per 

 ton per inile. Secondai-y haulage the writer suggests improvements in, and 

 states the present cost is from \s. '2d. to Is. %d. per ton per mile. 



Improvements which may he effected, applicahle especially to Working 

 Coal from Great Depths. 



Namely : — (1) Winding and Pumping ; (2) Ventilation; (3) Dealing 

 with high temperatures. 



1. Winding and Pum,ping. 



The mechanical difficulties arise chiefly in the design of winding 

 engines. Special winding plant and appliances associated therewith are 

 required for producing large outputs from an increased depth to com- 

 pensate for the heavy increase in capital outlay, and in loss of interest 

 due to the extra time required in establishing a deep winning. 



