INDUSTRIES 



The three forms of haematite already 

 noticed are vein-like, bed-like, and irregular 

 or patchy masses. The working of each is 

 described in the above paper as follows : 



VEIN-LIKE DEPOSITS (figs, i and 2). 

 The usual method of working vein-like ore 

 may be briefly described. Having sunk 

 the shaft in a suitable position, levels are 

 driven off at right angles to the ' fault ' at 

 distances from 120 to 180 feet apart ver- 

 tically, the number of levels depending on 

 the extension of the vein in that direc- 

 tion. After the ore has been intersected 

 and its width proved, longitudinal workings 

 are commenced right and left, ' rises ' are put 

 up on the footwall as the various workings 

 advance, the pillars between each 'rise' being 

 from 60 to 70 feet in length. Intermediate 

 horizontal workings are then driven from the 

 'rises,' middlings of from 15 to 30 feet being 

 usually left between, and thus the system of 

 splitting up the vein goes on. The ' rises' form 

 hoppers, shoots, or (as locally termed) ' hur- 

 ries ' for conveying the ore from the inter- 

 mediate workings to the different levels 

 communicating with the shaft. Until com- 

 munication by means of the ' rises' has been 

 effected with the different levels, the ventila- 

 tion of the workings is obtained in the usual 

 way, viz. by bratticing of brick or canvas or 

 by wooden boxes. 



In the case of a wide vein, say from IOO 

 to 1 2O feet, two longitudinal workings may 

 be driven right and left from the shaft-drift, 

 care being taken in so doing to ' blind ' the 

 opposite workings, not only to strengthen the 

 drift, but as a safeguard in carrying on blast- 

 ing operations. Unless the hanging and foot- 

 walls are of a strong character, it is advisable 

 not to drive the workings close to them, but 

 to leave a portion of ore against them for sup- 

 port. The size of the workings varies from 

 8 to 2O feet wide and from 8 to 12 feet high. 

 These dimensions are, however, altogether 

 regulated by the nature of the ore : where 

 that is very hard and free from joints or 

 cleats, larger workings than those stated may 

 be safely carried on, and in such cases little 

 or no timbering may be necessary. This 

 however is the exception, not the rule, as in 

 most deposits the character of the ore is sub- 

 ject to frequent changes, and renders timber- 

 ing necessary to a greater or less extent, even 

 in the first series of workings. 



BED-LIKE DEPOSITS (figs. 3 and 4). The 

 usual method of working this class of deposit is 

 by the pillar and stall system. The pit is sunk 

 in a convenient position in the royalty and as 

 far as possible to the dip. When the ore bed 

 has been reached, and adequate provision has 



been made either by sump or lodge for con- 

 tending with the water, a level is driven at 

 right angles to the dip of the strata, while at 

 the same time a heading is carried on to the 

 ' rise.' As the branch workings on the levels 

 advance, stalls, bords, throughs or (as locally 

 termed) ' thirls ' are commenced, leaving pil- 

 lars 24 to 45 feet in length. From the head- 

 ing also other workings are branched off, with 

 from 1 8 to 36 feet of solid ground between 

 each. The pillars thus formed (when the 

 ' thirls ' from the various level workings are 

 holed) measure from 430 to 1,620 square feet. 

 Smaller pillars will suffice in the case of very 

 hard and strong ore. 



The width and height of the workings de- 

 pend very much on the hardness and thickness 

 of the ore and the nature of the roof. In the 

 case of very hard ore with a good strong 

 roof, and where the thickness of the bed will 

 permit, the workings may safely and with ad- 

 vantage be made from 15 to 20 feet square, 

 but where the ore is tender they are usually 

 driven from 9 to 1 2 feet square, while timber- 

 ing in the latter case is necessary, more 

 especially if a shale-bed (as very often hap- 

 pens) overlies the deposit. No definite di- 

 mensions, however, can be fixed for regulating 

 the size of the workings in these deposits, as 

 can be done, for instance, in the working of 

 the thicker coal seams, as the varying con- 

 ditions met with render it impracticable. 

 The engineers or managers of these mines 

 require therefore to exercise their discrimina- 

 tion and bring practical experience to their 

 aid in coming to a decision on this point, 

 although the writer thinks that in many in- 

 stances errors of judgment have sometimes 

 been committed (especially in the earlier 

 working of these deposits) in making the first 

 workings both too high and too wide, and 

 thus not only incurring considerable risk to 

 life, but likewise causing great loss of mineral 

 to the proprietors of the mines. 



The main heading is frequently used as the 

 trail-road for bringing the ore from the work- 

 ings to the shaft, and so long as the gradient 

 is light, ' skutches ' or sprags are used in 

 running the loaded bogies or tubs down to 

 the level drift. It frequently happens, how- 

 ever, that the beds rise at so steep an angle 

 as to necessitate the making of an incline, 

 worked either by a wire rope or chain pulley, 

 or by a drum furnished with an efficient 

 brake. As the gradients of the beds are 

 variable, sometimes running nearly flat and at 

 other times at a steep angle, a series of in- 

 clines are frequently in use in working a de- 

 posit. The full bogies (one or two at a 

 time) bring up the empty ones, and swinging 



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