« ՆախորդըՇարունակել »
Cumberland Mountains, 1.450 2447 Ohio, 1.270 2140 Mean weight in the U. S.
1.250 / 2106 Indiana,
1.260 2126 Pennsylvania,- Anthracites. Illinois, 1.273 2146 Lykens valley,
1.327 2240 Average in U. States.
2160 Lebanon co., grey vein, 1.379 2327
Schuylkill co., Lorberry c'k, 1.472 2484
Pottsville, Sharp Mountain, 1.412 2382 EUROPE.
1.446 2440 Salem vein,
1.574 2649 England.
Tamaqua, vein N.,
1.600 2700 Newcastle, cherry coal, 1.266 2136 Mauch Chunk,
1.550 2615 caking, 1.270 2143 Nesquehoning,
1.558 2646 Wigan, 1.275 | 2151 Wilkesbarre, best,
1.472 2484 Durham, 1.274 | 2150 West Mahonoy,
1.371 2313 Lancashire, cannel, 1.199 2023 Beaver Meadow,
1.600 2700 Derbyshire, furnace coal, 1.264 | 2133 Girardville,
1.600 2700 Shropshire, 1.268 2140 Hazelton,
1.550 2615 Broad Mountain,
1.700 2869 Scotland.
1.609 2715 Glasgow, cherry coal,
1.268 2140 splint,
1.307 2205 Massachusetts. Wylam, 1.302 2197 Mansfield,
1.710 2885 Edinburgh, cannel,
Rhode Island. France.
1.810 3054 Puy-de-Dôme, 1.3102212 Average in U.S.
1.300 2193 Auvergne,
1.330 2244 South Wales.
1.263 2131 Belgium.
1.337 2256 Hainaut, 1.270 2140 average,
1.350 2278 Liege, 1.300 2193 Ynis-cedwin,
1.445 2376 Frederich,
1.263 2131 Gustaw grobe,
1.270 2140 France. Average in Europe. 2164 Allier,
1.380 | 2207 antal,
1.390 2283 Brassac,
1.430 2413 ASIA.
Belgium, anthrac's coal of Bengal, Hurdwar, 1.368 2308 Mons,
1.307 2105 Chirra Punjee,
1.350 2278 Assam, Kosya hills, 1.275 2151 Prussian Saxony,
1.466 2474 Aracan, Birmese,
1.300 2193 Average in Asia. 2277 Average of Europe.
2281 From the foregoing table several useful facts are made apparent. The first is, the greater weight of the American anthracites than those of Europe ; second, that the bituminous coals very closely coincide in both quarters of the globe.
Average weight of a cubic yard.
Mean weight of the American, 2560 lbs.
2277 We have neither added the weight of the intermediate species of coal to the bituminous column nor to the anthracites; because, in either case, it would have unduly affected the true character of the averages.
regards the table of American anthracites-and it may be correct also to include that of the bituminous coals—it will be seen, with the assistance of a map, that their specific gravity increases as we advance from west to east : confirming also the fact, noted elsewhere, that the weight of the combustible decreases in proportion to the amount of bitumen with which it may be charged.
The Anthracites of Pennsylvania, commonly distinguished as White Ash, or Red Ash Coals, and selected according to their respective qualities.Whilst treating on the comparative value of the varieties of Pennsylvania anthracite, as applied to iron making, we have said but little in relation to their relative values for domestic use. It seems established that, for closed furnaces, for warming houses, the white ash variety, being the most compact, dense, and slow burning, is more durable, and consequently, more preferable than the softer red ash coal. In open grates, for warming apartments, the latter is decidedly preferred. We have observed a recent statement of the result of an experiment, in relation to this point, which, as regards the warming of apartments, seems tolerably decisive.
A very important and interesting experiment was recently made for the purpose of testing the comparative value of the red and white ash coals for domestic purposes. Two rooms of nearly the same size, and having the same temperature, were selected to ascertain how many pounds of each kind would be required to heat them to a temperature of 65 degrees, during a period of 15 hours, when the temperature out of doors at 9 A. M. was at ten degrees below the freezing point. Two days were occupied in the trial, so that the red and white ash coals might be used in alternate rooms. Fires were made at 9 A. M. and continued until 12 P. M. Two thermometers (one in each room) were suspended at the greatest distance from the grates, and the temperature was carefully registered every hour. The result was as follows:
Thirty-one pounds each day of the Schuylkill red ash coal gave a mean temperature of 64 degrees; and thirty-seven pounds each day of the white ash, taken from a vein of high repute in the Lehigh region, gave a mean temperature of 63 degrees. Making, 2000 pounds of the red ash to be equal to 2387 pounds of the white; or, red ash coal at $5.50 per ton, to be equal to white ash at $4.61. This settles the question on the score of
DEPTHS OF COAL MINES. The following statement has been prepared from a much more extensive series, in order to exhibit the minimum, the maximum, and the average depths beneath the surface at which beds of coal are at this time productively worked, in the principal mining regions of the world.
Depths of Coal Mines. No. of Coal-Fields. Coal-Fields.
Minimum Average Maximum
No. of Coal-Fields.
Depths of Coal Mines. Minimum Average Maximum
feet, feet. feet.
Great Britain. xx.S Yorkshire, near Wakefield,
Derbyshire, near Chesterfield,
The Swan Banks colliery, near Halifax, XXIII. Whitehaven, Newcastle, Tyne district,
Wear district, MonkwearXXV.
mouth, Do. Murton colliery,
Tees district, XXVI. Berwick upon Tweed. XXIX. Victoria colliery, Nitshill, Glasgow,
Scotland, deepest mine,
Duffryn colliery, near
Alais, in Gard, XVIII.
Decize, in Nievre,
Liege province, L'Esperance
mine, at Liege, 450 metres, North America, United States. In this country, the short period in which the coal beds have been worked, has not occasioned the sinking of vertical shafts to any considerable depth.
The deepest anthracite mines of Pennsylvania are commonly worked by sloping shafts, which follow the inclination of the seams.
In numerous positions the coal can be mined by adit level as in Wales, several hundred feet below the moun
SYSTEMS FOR WORKING COAL MINES. We have devoted but small space to this subject; not that we are insensible of its extreme importance, but because it was somewhat out of the scope we had assigned to the present volume, and also because this knowledge may be separately obtained through the medium of numerous publications by experienced persons; conveying that precise description of information, for the benefit of those who are practically engaged in this service, or are interested in this description of property. It would be invidious, perhaps, to make mention of some of these, without including all.
The Parliamentary Reports embody a great amount of practical information on the methods employed in excavating coal mines. The pages of the Mining Journal, during many years, have been rich in valuable details of the same kind : and among the most recent of its articles is one from Mr. Dunn, “on the various systems practised in the conducting of coal mines, and of the methods employed in counteracting the effects of inflammable air.”* This article has elicited criticism and additional facts from others, equally paractical, through the same useful channel.
This subject is also treated on at some length, in Dr. Ure's Dictionary of Mines, &c. The method of working the thick coal veins of France will be found in the present volume, at page 332, showing the practice adopted in the mine of Blanzy. The mode of working the main or ten yard coal at Dudley, in England, is also described at page 286 and illustrated by fig. 20.
At page 420, we have supplied a brief account of an extremely interesting coal mine, that of Anzin, in the coal basin of Valenciennes. The coal measures are here, as at Mons in Belgium, covered by an enormous thickness of horizontal cretaceous and tertiary strata, through which it is necessary to penetrate. These overlying beds are called by the French miners "moris-terrains," or dead lands, and being highly charged with springs of water, require great skill and enormous expense in sinking the shafts through, until they reach the inclined coal seams, at the depth of from two hundred and twenty to eight hundred feet beneath the surface.
In order to show more distinctly the position and arrangement for the ventilating fires at the bottom of the shafts, we introduce the following enlarged figure of those employed in the mines of Anzin.
Diagram showing the arrangement of a ventilating furnace, “ foyer d'aerage."
* Mining Journal, March 21 and 28, 1846. The reader will derive much interesting information, respecting coal mining operations, from the lectures of Professor Anstead, as reported in the London Mining Journal, 1847-8.
The annexed figure affords a remarkably instructive view of these circumstances, both in a mining and geological sense ; showing the revetement or impervious lining of the shaft, through the “dead formations;" the mode of ascent and descent provided for the miners, and the position of the ventilating fire, near the bottom of the vertical' shaft.