May 7, 1915. THE COLLIERY GUARDIAN. 961 is sprayed at high pressure. The action of this mass of finely divided cold water beating suddenly on to the hot gas produces a sudden chill, which, together with the concussion brought about by the water, precipitates and washes, out practically all the naphthalene, which flows away along with the water into a catch tank beneath this apparatus. The naphthalene is filtered off, whilst the water is either allowed to flow away, or is re-cooled and used over again continuously. This cooler serves also the double purpose of extracting the naphthalene, as well as cooling the gases to the required temperature for extracting benzol. It is necessary to extract the naphthalene, otherwise it would pass on to the benzol scrubbers, where it would be dissolved by the benzol wash oil, which would very soon become saturated with naphthalene, and then rendered useless for the purpose of extracting benzol. The naphthalene so extracted is of a pale yellow colour, and finds such a ready sale as to amply justify the cost of running this part of the plant. The gas, now cooled, but still containing the benzol, r hi i View, looking West, showing General Arrangement qf By-product Plant. COAL WASTE IN CANADA—AND ITS CONSERVATION PROBLEM.* By Dr. Frank D. AoAMS.f In Canada, in the year 1913, the water power available on the turbine shafts of our electric installations amounted to 1,100,000-horse power. Assuming that under average conditions one horse-power hour can be produced in a steam plant from 31b. of coal, then 1,100,000-horse power calculated on a 12-hour basis, and taking a load factor of 50 per cent., which is a conser- vative allowance, represents a saving of 2,750,000 tons of coal per annum. When it is remembered that the total output of coal in Canada for the same year amounted to only 15,115,089 tons, these figures are all the more striking. It is also interesting to note that the development of our water powers is as yet only in its infancy, that an immense volume of power is annually running to waste, and that each horse-power per year which thus runs away unutilised is equivalent to the buaning up.and destruction of five tons of coal. thick that it is difficult, in fact in some cases impossible, to work the whole thickness of the seam at once. Con- sequently, the upper or lower part of the seam alone .is worked, leaving the rest behind. Again., where there are thin seams of coal alternating or interstratified with thicker beds in a series of measures,' the/ coal in the thicker seams, which are easily and profitably worked, is often extracted, leaving the thinner seams untouched. These—which could be worked at the.same time as the thicker seams at a comparatively small cost-—when the thicker seams have been removed and the workings have collapsed, are frequently so much shattered that the coal which they contain is for ever lost. In the methods of working a coal seam which are usually adopted, a large part of the coal is left in the mine during the working in the form of pillars for the purpose of supporting the roof. These pillars in the final stages of the mining of any area can be in part removed, 'but a large part of the coal, which hriv be stated to be on an average 50 per cent, of all the coal originally present in the seam, remains in the mine, and is permanently lost. The excessive use of powder also entails a loss of coal owing to the fact that it breaks up the coal, and in this way develops a relatively very large amount of slack, accompanied with increased danger from fire and explosion. All these causes of waste are illustrated in the coal- fields of Canada. It may be stated that in the coalfields of Nova Scotia the amount of coal which has been wasted is at least as great .as that which has been extracted. This is apart from and in addition to the coal neces- sarily left in the mines under the methods of mining employed. This waste amounts to very many tens of millions of tons. It is a satisfaction to note, however, that the greater part of the waste in question took place in the earlier years of the coal mining industry in this province, at a time when there was no effective Govern- ment supervision. At the present time every mining company operating under leave from the Government of Nova Scotia is required to submit in advance the plans which it is proposed to follow in opening up any coal seam. These plans must be approved by the Chief Inspector of Mines, under whose supervision the actual mining of the coal is also carried out. The waste of coal has thus been greatly diminished, and would be reduced still further were it not that in many cases it is now very difficult to introduce the best methods of extraction owing to the condition in which the mines have been left by the early operators. In the great coalfields of the provinces of Alberta and Saskatchewan, which are now commencing to be opened up, and whose mineral wealth is the property of the Dominion Government, by whom the right'to mine for coal in certain areas is leased for a certain definite term of years, the experience of the early days of Nova Scotia mining is now being, repeated. The Department of the Interior under the Dominion Government has mining passes first through the exhauster, and then through a tubular water cooler, which takes out the last trace® of moisture, and thence to the three large benzol scrubbers, each 9 ft. 9 in. diameter and 75 ft. high. These scrubbers are of such capacity that the gas flows very slowly through them, giving ample time contact for the absorption of the benzol. The lower portion forms a reservoir for the circulating benzol wash oil, and the remaining portion is filled with wooden grids. Benzol wash oil is constantly circulated over these grids, the gas having to pass through them. By this means the gas is brought into very intimate contact with the oil, with the resulting absorption of the benzol. The gas passes then into a gas holder, whence a portion of it travels to the ovens for heating purposes, whilst the remainder goes to the gas boosters placed in the exhauster house, which raise the pressure to 1511b. per sq. in. This surplus coke oven gas is then sent in a 16 in. welded steel pipe, the joints of which were welded in situ by the acetylene process to the Newcastle-upon- Tyne Electric Supply Company’s power . station at Dunston, about 1| miles distant, and where the recent extensions to the boiler house equipment consist of four gas fired water tube boilers, each capable of dealing continuously with 57,000 cu. ft. of gas per hour, built in two batteries, and two coal fired water tube boilers, each capable of producing continuously 30,0001b. of steam per hour. The benzol plant at Teams is arranged for the production of crude naphtha, and consists of two large cast iron light oil stills, complete with oil warmers or heat exchangers and oil pre-heaters. The benzol instal- lation is designed so that it may be superintended from the exhauster house. The coal washery, coal handling, and crushing plant was manufactured and erected by Messrs. Campbell, Binnie, Reid and Company, of Hamilton, N.B., to the specifications of the general contractors, the Otto Coke Oven Company Limited, of Leeds, who have been responsible for the execution of the whole of the works to the requirements of Mr. Ernest Bury, of Skinningrove., R.S.O., Yorkshire, as the con- sulting engineer, and Mr. A. W. Barnley, the resident manager of the Team By-Product Coke Company Limited, to the courtesy of whom the writer is indebted for permission to visit the works and publish the fore- going particulars and the accompanying drawings and photographs. Grimsby Coal Exports.—The returns for the week ending Friday, the 30th ult., show that the coal exported from Grimsby consisted of the following :—Foreign : To Arendal, 772 tons; Christiania, 1,572; Dieppe, 306; Esbjerg,. 731; Gefie, 1,503; Rotterdam, 1,868; and Ystad, 2,372—total, 9,124 tons foreign, as against 13,042 tons foreign, and 230 tons coastwise during the corresponding period of last year, .1 I ix *1/ '..W Interior of Exhauster House, showing Exhauster and Gas Boosters. While Canada contains abundant supplies of coal, the coal beds are chiefly in more or less inaccessible regions. The investigation into the coalfields and coal resources of Canada which was carried out in connection with the meeting of the International Geological Congress held in Canada in 1913; showed that less than 1 per cent, of the coal resources of the Dominion are situated in Nova Scotia and New Brunswick, while 87 per cent, lie in Alberta, much of this coal being in very remote districts of that province. The coal seams which are now being worked are those which contain the coal of the best quality and in the most accessible regions, and those which are nearest to what are and always will be the great centres of popu- lation in the.Dominion. They are, therefore, speaking generally, the deposits from which coal can be delivered most cheaply. When coal can no longer be obtained from these, districts, or if for any reason it becomes more difficult to extract coal from them, the price of coal will tend to rise. Again, there are beds of coal in Canada which are so * From a report to the Commission of Conservation, Canada. t Dean, Faculty of Applied Science, McGill University, Montreal. inspectors, whose functions after the leases have been granted consist essentially of collecting the royalties on the coal extracted; the respective provincial Govern- ments also have mining inspectors, whose duty consists in seeing -that the mining is carried on in such a way that the life and limb of the miners are safeguarded; but s