November 1, 1886.] 



♦ KNO^WLEDGE ♦ 



than those of any other country in Em-ope. It is purely for 

 the protection of the poor collier that we compel the rich 

 capitalist to sink two pits where otherwise, and in other 

 countries, only one is necessary. As the cost of a pit may 

 amount to ten, twenty, and in some crises to as much as 

 fifty or sixty thousand pounds, this legislative interference 

 with a fundamental industry is one of a multitude of 

 refutations of the shallow Napoleonic libel still repeated by 

 ignorant foreigners. 



The object of the two shafts is to secure efficient venti- 

 lation throughout the mine, one shaft serving as an inlet 

 for air, the " downcast " shaft ; the other as an outlet, 

 the " upcast " shaft. The object was formerlj^ attained 

 bj' dividing the .shaft do\vn the middle by a " bratticing " 

 or perpendicular wall of woodwork. Brattices are still 

 used in other countries, where the saving of rich men's 

 capital is deemed more holy than the saving of poor 

 men's lives. The catastrophe at Hartley, where a vibration 

 or swing of the cage caused it to strike and wreck the 

 brattice demonstrated the danger of this contrivance, and an 

 Act of Parliament justly abolished it. 



The diameter of ordinary modern coal-pits is from S to 

 12 feet ; some reach IG feet, and even more. Old pits of 4 

 to 5 feet diameter .still exist, but are now very r;ire. In this 

 country they are. with a few exceptions, circular. The excep- 

 tions are elliptical pits, which are more common in Belgium. 



It is Goldsmith, if I remember rightly, who tells the story 

 of an old paradoxical Chinaman who stopped strangers in 

 the street and asked them which are the more durable, 

 hard things or soft. On receiving the natural answer, he 

 opened his mouth and showed that all his teeth were gone, 

 while his tongue remained as waggish as ever. A similar 

 paradox is presented in pit sinking. Within certain limits, 

 the harder the rock to be penetrated the easier and less 

 costly the sinking of a given depth of shaft. The reason of 

 this is that a hard compact rock, such as the hardest among 

 the coal measures, has only to be removed so as to cut 

 thi'ough it a shaft of the required diameter. This being done, 

 the rock itself constitutes its own pit wall. But when the 

 rock is soft and friable, such as the shales that abound in the 

 coal measures, an artificial lining wall must be built all round. 



In ordinary cases this wall is made of brick. It is evi- 

 dent that the first excavation must exceed in diameter that 

 of the final shaft by double the thickness of this brick wall. 

 As it is unsafe to go lieyond a certain depth in friable 

 material without supporting it with this lining, the problem 

 to be solved is that of building a tower of brick from the 

 top downwards. If the ground is not verv bad, this is done 

 by first proceeding downwards (say from the compact rock) 

 ajid making the shaft of the same diameter as or smaller than 

 above. Having reached the depth of a safe stage, this 

 portion is now enlarged sufficiently to allow for bricking, 

 and then, as a foundation on which this brickwork is to be 

 raised, kerbs or courbes* — i.e., stout segments of wood, 4 to 

 6 inches thick perpendicularly, and the full horizontal width 

 of the intended brick wall — are firmly jointed together, 

 forming a stout wooden ring, which serves as a foundation 

 or floor upon which the circular brick wall is built up until 

 it reaches tlie finished i>ortion of the sh:ift .above. The 

 bricks used are of good qualitj', and accurately shaped as 

 segments of the circular wall requii'ed. The manufacture 

 of such " wedge bricks " is a regular business, the makers 

 keeping moulds for every required diameter. 



But how to sink below this kerb, seeing that the kerb 

 and all the wall that rests upon it must be supported while 

 it is being tindermined to build beneath it the next instal- 



* Courbe is the French name for this contrivance, and I may tell, 

 in passing, that the Welsh miners use the French word, so far as 

 pronunciation is concerned. How they would spell it I cannot say. 



ment of the tower ? Where there is a wooden kerb above, 

 safely resting on compact, reliable rock, this may be done by 

 means of " stringing deals " — that is, planks nailed against 

 the upper kerb or kerbs, and against each other if necessary 

 to join them in a string — the lower end of the string being 

 nailed to the lower kerb, which is thus supported firmly. 

 The sinking then proceeds as before down to another kerl>. 



The worst of all troubles in sinking is that which occurs 

 when " running ground " Ls reached, such as a deposit of 

 gravel. This is bad enough when tolerably dry ; but when 

 it happens, .as it usually does happen, that the gravel deposit 

 is a subterranean waterway, the cjise is very serious. I 

 cantiot better illustrate the nature of this, and the mode of 

 fighting it, than liy telling the story of my own experience. 



I was engaged as manager of the Leeswood works of the 

 London, Leeswood, and Erith Oil Company. Trouble came 

 upon us, in the first place, by a blow from America. There 

 they "struck ile,"' and also struck us, their petroleum, dis- 

 tilled by nature, being of the same character as our distilled 

 oil, but better in quality. When I commenced the distilla- 

 tion of this oil its wholesale price, refined, was 3.f. 6(7. per 

 gallon, now it is about Id. We could not produce it for less 

 than \s. Gd., if we purchased cannel from our neighbours. 

 A\'hen the price of American kerosine fell below this, our 

 retorts and my vocation were superseded. But the com- 

 pany had purchased a lease of land supposed to be rich 

 in cannel, and were sinking to it under the supervision of 

 the late Samuel Bl.ickwell, so well known in the Black 

 Country by his commercial enterprise and his commercial 

 misfortunes, and worthily respected in spite of the latter. 

 He visited the works weekly. We had a good underground 

 working foreman or " steward," whose name, of course, was 

 Jones (the population of those parts co^isists of men, women, 

 and Jones's, chiefly the latter). 



Poor Blackwell's health gave way, he knew that his brain 

 was failing under the pressure of trouble, and that he must 

 presently resign. We were close friends, and he initiated 

 me into the work to be done. I had already followed his 

 instructions, and paid the men, Sec, but was not a mining 

 engineer. At last Blackwell collapsed suddenly, and with 

 the help of the faithful Jones I did his work. This would 

 have been easj' enough had all gone well ; but one night I 

 was called up with the alarming intelligence that the pit 

 had given w.ay ; the whole structure of brickwork had sunk 

 some inches ; the sinkers had come upon loose ground, and a 

 total collapse was threatened. Either the shaft must be 

 abandoned, or the entire structure so far as it had gone 

 must be suspended from above. 



This alternative was no novelty to old hands, though 

 rather startling to myself. Jones was fully equal to the occa- 

 sion. A broad kerb was made of extra thickness, and this 

 was jammed under the base of the brickwork resting on the 

 " gravel wash," which was firm enough vertically while 

 undisturbed. The kerb was comjileted, each segment being 

 firmly keyed to its neighbour. Strong beams were then 

 jjlaced horizontally under this, and fully spanning across. 

 Similar lieams were laid across the mouth of the shaft, and 

 the top and bottom beams firmly connected by strong iron 

 chains similar to those used for raising the coal, &c. Then 

 the sinking w.as recommenced, but, as it proceeded down- 

 wards, the gravel trickled from the sides of the sinking into 

 the intended shaft, and thus opened out a cavern on all 

 sides far exceeding the diameter of the pit. The deeper the 

 sinking, the greater the diameter of this drift cavity. As 

 nearly as I can remember, about thirty feet of depth 

 was thus worked out. My anxiety was serious, doubtless 

 the greater from lack of familiarity. 



When I descended the pit and looked upwards there was 

 a brick tower about 150 feet high, suspended by the chains 



