54 



♦ KNOAATLEDGE ^ 



[January 1, 1887. 



tliat he fell down dead." * This is again the victory of day 

 over night. 



According to a Passamaquoddy myth, " Glooskap was 

 born in the land of the Wabanaki, which is nearest to the 

 sunrise," where he now dwells. Another story relates that 

 he came over the sea in a great stone canoe, and that 

 the canoe was an island of granite covered with trees. 

 " When the great man, of all men and beasts chief ruler, 

 who had come down from this ark, he went among the 

 Wabanaki." The Indian-English of the above is rather 

 obscurely expi-essed in the following words : " Gloosecap 

 hat left from ark, come crosse even wiht wabnocelel." f 



COAL. 



By W. Mattieu Williams. 



'PPOSING all the difficulties of sinking de- 

 scribed in my preceding papers have been 

 overcome and the seam of coal is reached, 

 the work of sinking is not yet quite finished. 

 The shaft has to be continued downwards 

 through the seam itself, and a few yards below 

 that. This latter extension is to obtain a 

 " sumpf," or "sump," i.e., a well or tank for receiving the water 

 which makes its way through the sides of the shaft, and 

 will afterwards How from the workings. Until the works 

 are fairly opened, it is usual to draw the water from this by 

 means of a large iron bucket with a hole in the bottom, 

 which hole is plugged by a valve that lifts when the bucket 

 is immersed in the water and closes the hole by its own 

 weight, and the jiressure of water above when the bucket 

 rises above the level of the water in the sumpf. 



The contrivance for emptying this large bucket when it is 

 drawn to the surface is simple and ingenious. Instead of 

 tilting it over (it is commonly 5 or G feet deep and a 

 yard across), the plug valve has an iron pin attached to its 

 lower part, and projecting like a short tail below the bottom 

 of the bucket. The bucket is drawn np and raised a little 

 above the surface of the ground, then a wide wooden trough 

 is slid under it, and the bucket is lowered so that the pin 

 strikes the bottom of the trough, thereby lifting the valve 

 and allowing the water to flow from the bucket into the 

 trough, which conveys it to the waste- water channel. When 

 the roads are made and the pit is in full work a pumping- 

 engine is erected for raising the water, a work which in 

 some cases is very costly. 



As already explained, the pit is usually sunk at the lowest 

 part of the seam included in the "royalty "or area to be 

 worked from it, but for reasons that will be readily under- 

 stood, the working of the coal is not commenced here. In 

 the first place, if the coal were removed from immediately 

 around the shaft the ground would give way, and the shaft 

 itself become a ruin. Besides this the roads required to 

 reach the distant parts of the coal, and to biing it from 

 them to the pit would be liable to extinction by burial. 

 Therefore, the usual mode of proceeding is to begin at the 

 outer or furthermost boundary of the royalty, and work 

 backw.ards towards the shaft. 



In order to reach this outermost portion drifts must be 

 cut to serve as roads for bringing the coal to the shafts, and 

 as channels for the water and ventilation. These are kept 

 sufficiently narrow in the immediate vicinity of the shaft to 

 leave a substantial mass of coal around to serve as a " .shaft 

 pillar." 



In fome exceptional cases (as when an extension of the 



* Leland, "Algonquin Mvtlis of New England," p. 17. 

 t Ihiil. p. 21). 



royalty has been obtained after sinking the shaft) it is 

 desirable to work some of the coal on the deep side of its 

 incline from the shaft. The shaft itself is then sunk below 

 the extreme depth of the coal to be won, and a cross cut 

 made from it, enteiing the seam at a right angle or there- 

 abouts, so as to effect its drainage. Then the roads to this 

 portion of the pit descend from the shaft, and the coal has 

 to be drawn up them by engine power. 



I need scarcely add that the roads of a coal mine are very 

 nairow-gauge railways. They are, in fact, the parents of 

 all railways, this form of iron road having been first used in 

 coal pits, and used there long before they came into practical 

 operation above ground. The iron rails were preceded by 

 wooden rails. The main road of a colliery is called a 

 " mother gate " by old colliers. This word "gate" is used 

 underground according to its ancient Scandinavian significa- 

 tion. Gata is the old Norsk or Icelandic for a way or 

 road. Gat in modern Norsk and Danish means an inlet 

 or opening. Our colliers in this, as in many other in- 

 stances, still speak the tongue of Thor, the hammer-bearing 

 god of the primitive miners ; have deviated even less than 

 the modern Scandinavians themselves. A gate in subter- 

 ranean Engli.sh is not the thing which bars the way, but is 

 the way itself. Similarly the Northern expression " gang 

 your ain gate " means go your own way, not your own gait, 

 as commonly supposed. 



In driving a gate or road, whether horizontal or more or 

 less inclined, the Fame difficulty is encountered as in sinking 

 a single shaft. The air gradually becomes wor.=e and worse 

 as the driving proceeds, until at last special contri\'ances for 

 ventilation become necessary. Either the drift must be 

 divided by a contrivance similar to the brattice of a shaft, 

 or two parallel ways must be driven. The latter is usual, 

 a rib of G to 10 yards thickness being left between them. 

 The lower of these serves as the drain or " water gate," the 

 upper is the main road for men and waggons or the " way 

 gate." The side roads from the workings and the way-gate 

 are called " bord-gates." 



Where the seam is thick enough these drifts are made be- 

 tween the thill or floor (Icelandic again, thilja) of the coal and 

 its roof. If the seam is above 6 or 8 feet thick, some of the 

 coal may be left above to form the roof. If, on the other 

 hand, the seam is too thin, the rock above the coal or the 

 floor below is cut away to give sufficient height. The width 

 of such ways is economised as much as possible, as every 

 increase of width increases the dangers of falling roof and 

 " creeping." 



This creeping is very curious and instructive. I recom- 

 mend it especially to the attention of those mathematicians 

 who have gone a very long way from home in order to 

 determine the rigidity or viscosity of the earth's crust, and 

 whose very recondite calculations have so curiously con- 

 tradicted each other. As Sir William Dawson told us at 

 the last meeting of the British Association, " Hopkins, 

 Mallet, Sir William Thomson, and Professor G. H. Darwin 

 maintain the solidity and rigiditv' of the earth on astro- 

 nomical grounds, but diflferent conclusions have been reached 

 by Hennesey, Delaunay, and Airy." Sir W. Thomson espe- 

 cially contends that a great amount of rigidity is indicated 

 by the gravitation of the equatorial protuberance of the 

 earth upon the moon, and the moon upon the equatorial 

 protuberance. 



A study of the phenomena of creeping would, I think, 

 supply more reliable results as regards the viscosity of the 

 outer crust of the earth, and show that its rigidity is over- 

 come by a pressure which, cosmically regarded, is very 

 small indeed. 



This creeping is a gradual rising of the apparently solid 

 rock floor after the coal is removed from a considerable are,i. 



