January 19, 1917. THE COLLIERY GUARDIAN. 125 that known as the Swallowd.rum, which overlies about 40 fms. of whin. This seam is here called, the Swallow- drum, though in Dunfermline the Lochgelly Splint is known under that name. In other parts a coal called the Kinglassie Splint is worked, which may be the Swallowdrum mentioned. The next few fathoms brings in other three seams of coal, the lower, mid, and upper leaves of the Diamond or Jersey coal. It is only where the three leaves 'are close together that they receive those names. When further separated, as at Oakley, only two leaves, or, rather, two distinct seams, occur. The lower is called the Dcddie Davie, and the upper the Jersey coal. On the northern boundary the lower leaf is called the, Doddie Davie, and the cither two the lower and upper Caimoubbie. At Cuirass only one seam occurs, and it is called the Diamond, while in other parts this .so-called Diamond has an upper and lower leaf. From a few feet to as many fathoms above this Diamond or Jersey coal is found the Main or Fourteen- feet coal. At Lochgelly this seam is 15 ft. thick, while at Saline it is 3 ft. thick, and at Oakley it is wanting. In Kirkcaldy district the name given to this seam is Splint and Rough or Glume coal. While it cannot be said that, this seam is continuous throughout the entire area, it is much more regular than the seams imme- diately underlying it. Over a large area this seam is much broken up by what are known as “jacks,” i.e., small dykes or wants in the coal. Where this coal is thick, and stoop and room method adopted, great care must be taken, as this seam is very liable to spontaneous combustion. In fact, large areas are at present sealed off in this seam. Above the position of the Main coal no seams of any importance occur, though several beds of ironstone have been worked, but not at present to any extent. Those seams of coal and ironstone where they were found have nearly all been worked out. The only seam of any importance just now is that known as the Little Splint, which is worked in the Lochgelly and Doni- bristle areas. The seam is up to 3 ft. 6 in. thick, but the area covered by this seani of a workable thickness is very limited. month for four months would aggregate' 8,000 dols. a year over any form of hand lamps. Other levels, cross- cuts, and drifts show the same proportionate saving. The management would not go back to hand lamps, nor do the miners working in the mine wish such a step. The hand lamp method of lighting is as obsolete from an efficiency standpoint as the hand drill is when com- pared to the pneumatic drill. The men always have a candle or two in their box near at hand, so that they can light one, if by any chance the wires should be broken and the lights gO' out, or if they suspect any gas they can light a candle and test it. AFFORESTATION OF PIT MOUNDS. The Midland Re-afforesting Association was estab- lished in 1903 to advocate the commercial planting of pit mounds, and other waste ground in South Stafford- shire. Such planting has been successfully practised for many years in most Continental coal fields, and perhaps it is only the general backwardness of forestry in this country that Iras prevented its becoming general in England, Wales, and Scotland. But the idea was more or less new to Britain. Some land owners in British coal fields had planted up pit mounds, and one colliery company at least had, for years, drawn pit props from its own spoil banks. These were, however, and still are, isolated cases, and the association had to contend with very great apathy and very general mistrust. It was, therefore, very difficult to get any planting done, and practically impossible to secure areas large enough to be really remunerative. A few small areas were, however, planted in 1904, and one larger one in 1905 (34 acres); but the association, had to make the best of what sites it could get and establish model plantations, in the hope that when the growth of timber in them was seen, it would be possible to go to work on a sufficiently large scale. These model plantations hove now served their turn. They number 35 in all, besides the large plot of 34 out. One part is still hot, and has therefore been left unplanted. On the sticky grey shale black alder has been planted, birch on the burnt out part, a very loose and friable soil, and black Italian poplar on the lower slopes. There are also a certain number of willow, sycamore, and wych elm, chiefly at the foot of the mound, while a few white alder, robinit (Acacia), and Sitka spruce have been planted in suitable soils by way of experiment. The whole mound, apart from the. hot area, is doing well. The growth has been excellent, and all the species named above are good. It is only fair to add that a few thorn and Austrian pine have been tried, but have not done well, and that the soil is hardly good enough for sycamore. The trees were mostly two-year 'transplants, but in some cases three-year transplants, when planted out in 1907, 1908, or 1909; and the measurements taken in November 1916 are very satisfactory, for few, if any, of the trees were 3 ft. high when planted out. The pre- sent measurements are :—Poplar (north-east side), 18 to 19 ft., girth 11 in. at 3 ft. from the ground; black alder, average 17 ft. 3 in., with 7} in. girth; birch, 17 ft., with girth 71 in. There are larger trees than these in some of the plantations formed by 'the association, but the even growth of Black Wagon—due, in part, to close planting—is its great feature. Birch, alder, and poplar are not high-grade timbers; but they are particularly useful in South Staffordshire, because there is a vast demand for them in Birmingham and in some of the Black Country towns. The two former are much used by turners for the wooden handles or other fittings for the countless objects made in the district out of iron or other metal. Poplar—when large enough—is much used for brake blocks. Before the war the price of birch and alder was 28s. per ton, and the wood could be used down to little more than an inch in diameter. Thus the price was much better than that of larch, whilst the period of growth is several years less. When the association began work, it was found that UNDERGROUND ELECTRIC MINE LIGHTING.* Underground Lighting in mines'has been viewed from various angles, and at the present tame there are in use the open oil lamp, the Davy lamp, the candle, the carbide lamp, and the electric battery lamp fitted 'to the miner’s cap. Electric lights are now quite com- monly used in underground lighting. The particularly advantageous feature in wiring a mine to have it well lighted throughout is the safety it provides by having all parts of the mine permanently lighted; but the comparative value of electric lights over hand lamps has never been extensively discussed. There are a few who contend that electric light will not give any indication of bad air, while a candle or an open flame will go out and warn the miner of the danger. This argument can be met with the answer that if bad air be suspected, an open flame can be used as an indicator. With regard to the cost of electric lighting in the Buckeye mines, the following particulars will give some actual comparative figures. A drift in one level is 1,200 ft. long, and two up-raises are working from that level. From the station to the breast, and up the man- way of the up-raises, there are electric light globes, pro- tected by wire guards, to within about 50 ft. of each face. There are 32 lights on this circuit, at varying distances from 50 to 75 ft. apart, depending on turns or conditions. The circuit is equipped with 40-watt incan- descent tungsten globes. Each working crew is pro- vided with an extension cord, with a lamp on the end of the cord, also protected by wire screen guard. With this extension cord the miner makes a connection at the nearest light socket to where he wants to work, strings the cord back out of the way, and carries the globe to his working face, and hangs it up behind him. In this way the entire working place is flooded with light. He does not have to bother with his light again until he is through with his shift, and ready to blast. Then he carries out his light, winds up his extension cord, and puts it in a safe place. Altogether there are 38 40-watt tungsten globes burning in this drift and the up-raises, which consume 1,500 watts on the meter every hour, at a cost of 44c. an hour, or 35c. per eight- hour shift for the dirift. There are eight men employed in this drift on the working faces connected with it, including the trammers; thus the electric lights cost 4|c. per shift per man in this drift. If there were 20 men, the lights would cost about 2c. per shift per man. The efficiency of this method of lighting is shown in the fact that when a man walks through a drift he walks at his natural speed, and is not groping his way in the dark, or trying to protect his light from draughts or wind. The lights never go out, and no time is lost adjusting them or handling them. The man works with the same physical efficiency that he would work on the surface or in a factory that was well lighted, and the actual results obtained show that the men accomplish 33 per cent, more work when the mine is electrically lit throughout than when working with hand lamps. The cost .of the operations in this draft are at the present time 2,000dols. a month, including miners’ ■wages, supplies, and its proportion of the overhead expense. As the progress and actual results obtained are 33 per cent, more than they were with any form of hand lamp, it is found that exactly as much is accom- plished in three months as previously took four months, and therefore the entire operating expense of one month has been saved every quarter of a year; or, to continue the same basis, exactly the same is accomplished in 12 months as was previously done in. 16 months with the hand lamps. Therefore, the saving of 2,000dols. a * Letson Balliet. .Mining and Engineering World. Black Wagon Mound, planted with Birch, Wych Elm, Acacia, etc. I acres, mentioned above. Not all have done equally well, and one or two are more or less failures, or have had to be given up because the land was imperatively wanted for some other purpose. But the cause of partial failure is in each case known, and, with the know- ledge gained by such partial failures—for no plantation has failed completely—the association has managed to establish a routine which seems well suited to the dis- trict and to the sometimes difficult conditions. The rate of loss is certain to be greater in small woods than in large, and the rate in the smallest of the association’s plots is not high. The association has planted on various terms. Some plantations have been formed for the land owners, the association doing all fencing and planting at a contract price, watching progress, and replacing dead trees for an agreed time. Others the association has taken on lease, the trees, in such case, being the property of the asso- ciation; and in such cases proper covenants are neces- sary a.s to determination of the lease, should the land be wanted for other specified purposes. In. a few cases the association has given the trees, and has managed and superintended the planting on behalf of some public body which has supplied the labour and owns the land. It is obviously impossible to spend subscribers’ money in improving the land cf any private firm or person. The plots held on lease by the association are three : Leamore, near Bloxwich, 11- acres, planted in 1906; Black Wagon, Old Hill, 2| acres, planted in 1907-09; and Littleton Street Mound, West Bromwich, 5 acres, planted in 1911-12. Of these, the second has been selected for more particular description, because it is varied in its soil, and typical, to some extent, of the chief kinds of mound in the district, while it is old enough for the measurement of its trees to have some meaning. Black Wagon Mound consists partly of grey shale and partly of shale mingled with a certain amount of slack. The slack has fired, and much of the mound is burned it cost about £5 to prepare and plant an acre with trees 5 ft. apart each way, that is, 1,742 per acre. The price of labour was, however, rising, and consequently the cost of planting, whilst experience has shown that plant- ing at 4 ft. distances—2,722 per acre—is a great gain on wind-swept mounds. What the cost is likely to be immediately after the war is hard to say, and numerous factors must be considered, but it is not likely that the cost would be above .18 per acre, even if planting at 4 ft. distance became the regular rule. Fencing, again, is an expense that must be faced, and the association has been able to erect a reliable fence at Is. per yd. After the war it may be more, but the total cost of fencing and planting is not in any case high. What the association has done is to show that sound plantations of certain selected trees can be grown on pit and spoil mounds. The land is poor, and can hardly be turned to agricultural profit. The trees grow with a minimum of attention, and the market is safe. Not every colliery district has such a market as Birmingham for its small, young timber, but each has its own trades which demand small timber, and the timber supply for many years will be behind the demand. Some districts could grow coniferous wood, for which South Stafford- shire does not appear to be suitable, but all districts ought to organise themselves to supply a very certain shortage of timber, instead of leaving thousands of acres which bring in no rent and no profit, and are merely eyesores to those who dwell among them. A London firm desires to obtain agencies in Hong Kong for United Kingdom manufacturers of electrical and mining machinery ; steam, electrical, and stationary engines ; haulage and traction engines, and general machinery for industrial purposes. The name and address can be obtained from the Department of Commercial Intelligence, 73, Basinghall- street, London, E.U. The reference (No. 10) should be quoted.