Page:Encyclopædia Britannica, Ninth Edition, v. 6.djvu/98

Rh 78 O A I PRODUCTION. principal production of patent fuel in Britain is in South Wales. The anthracite coal of Pennsylvania is subjected to the exceptional treatment of breaking between toothed rollers, and an elaborate system of screening before it is fit for sale. The largest or lump coal is that which remains upon a riddle having the bars four inches apart ; the second, or steamboat coal, is above 3 inches ; broken coal includes sizes above 2 or 2f inches ; egg coal, pieces above 2 j inches square; large stove coal, If inches; small stove, 1 to 1 or 1 inches; chestnut coal, f to inch; pea coal, $ inch ; and buckwheat coal, inch. The most valu able of these are the egg and stove sizes, which are broken to the proper dimensions for household use, the larger lumps being unfit for burning in open fire-places. Proportion The proportion of coal utilized in the working, as com- of coal ob- p are d with the total contents of the seam, varies very tained in considerably in different districts, being greatest in seams of moderate thickness, from 3 to 5 feet, which on the long-wall system can be entirely removed. In thick coals, such as the ten-yard seam of South Staffordshire, the waste is very considerable. In Cheshire and Lancashire about 1330 tons of saleable coal are obtained from an acre for each foot of thickness in the seam, only 8 per cent, of the total being left behind in the workings. At Dowlais, on the north of the South Wales coal-field, the yield is 1190 tons to the foot by long-wall, but only 866 tons when the same seam was worked by the pillar and stall system ; but on the south side of the basin, where the seams lie at a steep slope, the loss is often much greater, being from 20 to 50 per cent, on pillar and stall workings. In the Barnsley district, the yield is from 1150 to 1280 tons in thick seams, and a maximum of 1417 tons has been obtained in a thin seam, the solid contents of the whole coal being estimated at 1556 tons per foot per acre. In Northumberland about 1200 tons are got out of a total of 1300. In the thick coal of South Staffordshire, from 12,000 to 16,000 tons per acre are got at the first working on an average thickness of 25| feet, or about 640 tons to the foot, or from 50 to 60 per cent, of the whole, which is increased by the second and third working to 70 or 75 per cent, making a loss of from 25 to 30 per cent. This amount is reduced, however, by the long-wall method of working. Probably from 10 to 15 per cent, may be taken as the unavoidable loss in working under the most favourable conditions, but in many cases the proportion is consider ably higher. Ownership In the United Kingdom the ownership of coal, like that of other minerals, is in the proprietor of the soil, and passes with it, except when specially reserved in the sale. The greater number of collieries are worked upon leases, the rents or royalties being variously charged in different localities. A minimum reserved rent to cover a certain output, with a rate per ton on any quantity in excess, is the most general practice ; but in Lancashire and York shire the royalties are charged at a fixed rate per acre per annum upon each seam worked, and in South Staffordshire at a proportion (from to -fa) of tho coal at the pit s mouth. Coal lying under the sea below low-water mark belongs to the Crown, and can only be worked upon payment of royalties, even when it is approached from shafts sunk upon land in private ownership. In the Forest of Dean, which is the property of the Crown as a royal forest, there are certain curious rights held by a portion of the inhabitants known as the Free Miners of the Forest, who are entitled to mine for coal and iron ore, under leases, known as gales, granted by the principal agent or gaveller representing the Crown, in tracts not otherwise occupied. This is the only instance in Great Britain of the custom of free mining under a Government grant or concession, which is the rule in almost every country on the Continent. The working of collieries in the United Kingdom is Coal subject to the provisions of the Coal Mines Regulation rtegi Act of 1872, 35 and 36 Viet. cap. 76, which is ad ministered Act&amp;gt; by inspectors appointed by the Home Office, and forms a complete disciplinary code in all matters connected with coal-mining. Among the chief provisions of the Act are the following : 1. Females and boys under 10 are not allowed to work under ground. 2. Boys between 10 and 12 are not allowed to work except in tliin mines. 3. No boy under 12 to drive a gin horse, or under 18 a steam- engine. I. Wages not to be paid at public-houses. 5. Working of mines by a single shaft prohibited. 6. Managers to be certificated as competent by a board of examiners. 7. Annual return of coal wrought to be made to Inspectors. 8. Notice of accidents to be sent to Inspector. 9. Openings of abandoned workings to be fenced. 10. Plans to be kept up to within six months of date. II. Plans of abandoned mines to be deposited with Home Office. 12. General rules for the safety of miners in fiery mines, man agement of ventilation, safety lamps, and gunpowder, protection against accidents in shafts and levels, &c. 13. Power to frame special rules subject to approval of the Secretary of State. Breaches of the provisions of the Act are punishable by fine and imprisonment by a court of summary jurisdiction, subject to appeal to the Quarter Sessions, or to the Circuit Court in Scotland. The relation between the number of hands employed 1 ro and the output of collieries varies considerably in different of * districts, being highest in those where the coal is moder- out - ately thick, soft, easily cut, regularly shaped, and with a good roof, and least in faulted and disturbed seams, and those with a bad roof, where the accessory operations of timbering and driving stone drifts require the employ ment of a large proportion of the working staff on non productive work, i.e., other than cutting coal. The follow ing figures give the relative force employed above and below ground in two large steam-coal collieries in South Wales, each producing about 500 tons per day : Colliers cutting coal 225 200 Other underground hands 229 174 Surface hands 43 36 497 410 showing in the one case an average of about 1 ton, in the other about 1^ ton per hand per day, but if the hands cutting coal be alone considered, the amount is about the same in both cases, or a little over two tons per day. The annual output per man on the total force employed in several of the principal European coal-fields has been computed as follows : Newcastle 315 tons per man per annum. Westphalia 215 Saarbriicken 170 France Loire 200 ,, Nord 149 Belgium Charleroi... 147 Mons 121 These figures refer to some years back, and are probably not quite accurate at the present date, as the amount of work done by the individual collier has sensibly decreased in most countries. It will be seen that the output is smallest in the thin disturbed measures of the Franco- Belgian coal-field. In Prussia in 1874, with an output of 33,000,000 tons of coal and 8,000,000 tons of lignite, the average per