519 September 10, 1915. _____________________________________ THE COLLIERY GUARDIAN. _________________________________________________________ using purchased power. The power and book value of complete plant erected for gold and coal mines is shown below:— Gold mines and allied concerns. ________________ Coal mines. ________________ H.P. Valued). H.P. Value (H.P.). Transvaal ........692,160...30,223,798... 18,252... 974,965 Cape ............... 30... 793... 664... 40,959 Orange Free State 42... 2,500... 2,837... 131,751 Natal ........................ 311... 19,854... 14,084... 679,907 Total (Union)...692,543...30,246,945.. .35,837... 1,827,582 General Remarks. Reporting on the Johannesburg inspectorate, Mr. W. Moses states that change houses are being greatly improved in every way. At some of the mines hot coffee is served out to the white underground employees. The two large circular shafts on the Crown and City Deep mines have been most successfully sunk during the year, making a record as to footage, cost, and freedom from accidents. Sand filling is being carried out at most of the mines with sand taken direct from the tanks through boreholes sunk from the surface for the purpose. During the year experiments have been tried on the sand dumps to reduce the nuisance of the sand blowing over the neighbourhood. Success has been achieved by spraying over the dumps with slimes and salt. This process has now been adopted by the mines in this district. Large centrifugal pumps ‘‘ elec- trically run ” are gradually taking the place of ordinary force pumps. The water has to be particularly clean, and if passed through filter presses the pumps give most economical results. Electric blasting in stopes intro- duced last year at one of the mines has not caught on at other mines owing to the expense of installation. During the latter portion of the year portions of the shaft pillars on two mines in this district crushed due to pressure. These occurrences took place on the Village Main Reef and Ferreira Deep properties. In both cases the crush was accompanied by severe earth tremors recorded at the Union Observatory, Johannes- burg. In both cases the stopes against the shaft pillar in the vicinity of the crush were more or less sand filled, but in no instance was there any evidence that this sand filling had in any way relieved the strain borne by the shaft pillars. In his report on the Krugersdorp inspectorate, Mr. Fergusson deals with the subject of missfires. He says a great deal of time has been expended in attending experiments, studying the el'f- ct of different explosives in varying amounts under varying methods of charging, and consulting with the managements with a view to obtaining greater safety generally, viz.:—(1) The use of a No. 8 detonator instead of the more commonly used No. 6 was tried and is still being carried on; (2) the use of fresh detonators only, each man taking a fresh supply daily instead of storing a quantity underground, was attempted; (3) it was endeavoured to increase the initial detonation still further with the aid of a small quantity of detonating fuse (trinitrotoluene); (4) the use of 40 pei’ cent, dynamite as a primer cartridge was tried, and now experiments are being conducted with the substitution of 40 per cent, dynamite entirely for stoping purposes, on the assumption that dynamite explodes more completely than gelatine. It is to be hoped that a continuance of experiments on these lines may eventually lead to improved results. Further precautions which have been suggested to the manage- ments, with a view to decreasing the number of accidents, include more extensive back stoping, which would also tend to reduce accidents from fall of rock, the provision of more effective means of cleaning the working faces, and the restriction of double-shift work. In his report on the Natal inspectorate, Mr. J. E. Vaughan says the coal industry has not had a fail’ chance in the past year. At the start of the year the < ollieries had hardly got over the coolie strike, when there was a strike of white miners, which caused a general disorganisation. After the labour troubles had been settled, work progressed smoothly, save for an occasional shortage of railway wagon--. Everything seemed to be favourable to the steady development of the industry when the war broke out, with disastrous effects to the Natal coal trade. In the concluding months of the year the coal trade recovered partially from the effect of the sudden outbreak of war; indeed it was wonderful that the output of coal kept up as well as it did. At the same time great difficulty was experienced in getting ships for export trade, so many boats, trading as colliers, being requisitioned by the Admiralty upon arrival in Durban. As is well known, much of the Natal coal is of little value as a steam coal, and many coal-bearing areas have remained unworked for that reason. It was found that some coal in the Vryheid district was very high in nitrogen, analysis giving as much as 2 5 per cent, of nitrog-n. The Natal Ammonium Company was formed to extract by-products, such as sulphate of ammonia, from the coal; a railway siding was constructed and orders for an elaborate by-product plant were placed in England and Germany. The outbreak of war,^however, caused an interruption in operations. Arrangements have been concluded by which all the plant will now be purchased in England. A German company also intended starting by-product extraction on the farm Veelsgeluk, in the Vryheid district, but again the war stopped operations. The actions of these companies directed general attention to the possibilities of a by-product industry in Natal, options were taken over many coal areas, and, in addition, the managements of some of the existing collieries have been discussing the advisability of setting up by-product plants in addition to their existing plants. Actual tests at a certain colliery gave 1241b. of ammonium sulphate and 21 gallons of oil to the ton: it is improbable that such high results as these would be obtained in actual practice. If it can be demonstrated by the Natal Ammonium Company or any other similar concern that a by-product industry wiU be successful in Natal, the gain not only to Natal, but to the whole Union, will be immense. It will enable large areas of coal, which would have remained untouched for years, to be profitably worked, and it will bring large numbers of white people into some of the most sparsely inhabited, but healthiest, districts of Natal. Mr. Vaughan has little hesitation in stating that but for the war, proofs of the possibility of profitably extracting by-products in Natal would have been by now established, and he looks forward with every confidence to the future of this new industry. The mining of the top seam is still attracting the attention of Natal mine managers. Where the seams are close together most of the mines are now attempting to work. the top seam, and at one colliery where the seams are 40 ft. apart work on the top seam has been commenced. The top seam, as a rule, has more “ slips ” in it than the bottom seam, and therefore requires more timber and attention; the quality is also slightly inferior, as a rule, to the lower seam. On the other hand, its extraction will very materially increase the life of the collieries, and will go far to avert the numerous gob-fires which would occur if it was left in, as has been the case in the past. In a recent lease which was drawn up between the owner of the coal rights on a farm and a colliery, it was stipulated by the owner that the top seam should be worked as well as the bottom. This shows that the wasteful policy of the past is now fully realised, and that this valuable seam will be extracted wherever possible, and not wasted as heretofore. While the supply of good steam coal in Natal is limited, it is satisfactory to know the possibilities which exist of extracting by-products from coal of inferior steaming quality. The supply of known good coal should be sufficient to keep the colony going for many years to come, in which time the use of oil fuel will have come in to such a large extent as to render good steam coals less necessary than at present. As an example of the quantity of gas that may be expected, the following incident may be of interest:—A recent borehole for one of the collieries, situated about 2 miles westward from the present shaft, struck the coal seam at a depth of 800 tt., and tapped a large quantity of gas, which became ignited at the boiler fire of the drill plant. The flame was only extinguished with difficulty. After the rods had been drawn the manager determined to ascertain the gas pressure. He therefore connected the lining tube to a pressure gauge, and then sealed up the top of the lining tube. The pressure quickly rose until the pointer registered the limit on the gauge, 150 lb. per square inch. This, however, was not the total pressure of the gas, for after a few minutes the steel lining tube commenced to rise out of the borehole, and the cock had to be opened to prevent it from being forced right out. As this area is one where new shafts are likely to be sunk in the near future, some idea can be gathered from this incident of the difficulties and dangers which will have to be encountered on account of firedamp. It would seem advisable that the new shafts should be located as soon as possible, and a bore- hole sunk between them, so that the gas could be given a chance to “ bleed off ” before shaft sinking is started, otherwise there will be serious trouble when the new shafts go down. _____________________________ THE FRENCH COAL TRADE. On July 9, M. Leon Perrier, the Deputy for Isere, intro- duced in the Chamber of Deputies an important measure, having as its object the amelioration of the situation which now faces the French coal consumer. The Bill, which has been sent to the Commission of Mines for further examina- tion, aims especially at the prevention of speculation on the part of those holding supplies of fuel. The text is as follows : 1. For the duration of war and for six months following, the price of coal shall be fixed in accordance with the conditions that follow. 2. For each coal concession in operation, the selling price of the coal, according to quality, shall be fixed by the Govern- ment, taking into account the average prices obtained in the five preceding years, and the actual conditions of work- ing. These prices are exclusive of extra sums charged for delivery. 3. In each Department the Prefect, acting on the advice of the Chamber of Commerce of the district, shall fix the selling prices of coals to the consumer, taking into account their origin, their quality, the cost of transport, and the normal rate of trading profit. ' 4. In each case miners’ wages and other salaries paid by mine owners shall not be lower than those paid on August 1, 1915. 5. For any breach of the requirements contained in the foregoing sections, and of those contained in Decrees or Orders made in the carrying out of the Act, the penalty shall be a fine of from 200 to 3,000 fr. and imprisonment of from six days to six months, subject to the application of Article 463 of the penal code. In the Colliery Guardian of June 4, 1915, an outline was given of the Dalbiez Bill, relating to the mobilisation of workmen in France, in the form adopted by a Commission of the Chamber of Deputies. The Bill has since been under discussion in the Chamber, and certain amendments have been adopted, the Bill subsequently passing through the Senate. In the course of the debate in the chamber, M. Thierry stated that at the end of June, the reduction in the number of miners employed in France amounted to 32‘5 per cent., entailing a loss of output of 40 per cent., or 50,000 tons per day, equivalent to 2,500,000 fr. in gold. The working of the French mines, diminished to the extent of 50 per cent, by invasion, had been carried on to the full extent in the mines still remaining in French hands, the output being equal to 20,000,000 tons per annum, or from 60,000 to 65,000 tons per day. That left a deficit of 20,000,000 tons. The freight charges on foreign coal had been quintupled. He insisted that the Dalbiez proposition if applied to miners would cause a further loss of 40 per cent, in the effective, and of 20 per cent, in the output, as it would be impossible to replace the labour withdrawn in the manner proposed by the employment of volunteers and reservists. Several speakers emphasised the fact that the Bill made no provision for extending the production of munitions, which might be regarded as more urgent than the enrolment of men for the Armies. M. Durafour urged that the interest of the nation lay not in enlisting more miners or artisans, but in recalling from the ranks those who were required to sustain the industrial organisation of the country. M. Valette stated that, of the mines still being worked by the French, there had been in every case a reduction in output during the first three months of this year, as compared with the first quarter of 1914. The principal mines in the Pas-de-Calais in the French lines are Bethune, Noeux, Bruay, Maries, and Ferfay. One of the grounds of complaint raised in the Chamber was that when the Minister for War in November 1914 came to the conclusion that it was necessary to recall from active service a number of miners, numbering in all about 30,000, in order to carry on work at these collieries, a number of men other than miners secured inclusion by misdescription, in order to escape the rigours of the battlefield. To remedy this inequality, MM. Valette and Cadot, two of the miners’ representatives, proposed that a special commission should be set up for each mine, comprising representatives of the employers and workmen. This amendment was accepted by the Government, who also undertook to remedy some of the grievances that had been spoken of. The text of the Dalbiez Act is published in the Journal Officiel of August 19. An important alteration is made in Article 6; according to this clause, the Minister of War may appropriate for Government munition works men who have been or may be mobilised, such as managers, engineers, workers, etc., providing that they have been engaged in their profession for at least a year in establishments of this character. Now, in the case of collieries, the “ delay ” is reduced to six months. When the Bill was before the Senate on August 11, M. Audriffed, in an interesting speech, made a special plea for the encouragement of the French coal mining industry. He pointed out that a change had latterly taken place in metallurgical practice, and that, when an installation for producing steel was erected at, say, Le Creusot or Saint Chamond, it was designed to work on coal raised in the neighbourhood, and that equal results could not be obtained with other coal, however excellent in quality it might be. He therefore urged that all facilities should be given for the import of foreign coal, in order to conserve the supply of special coal of this character for the purposes of war. _______________... EXPLOSIVES IN COAL MINES. Two New Explosives. An Explosives in Coal Mines Order has been issued by the Home Secretary, amending the Explosives in Coal Mines Order of September 1, 1913, by the addition of two new compounds. The Order may be cited as ‘ ‘ The Explosives in Coal Mines Order of August 16, 1915.” Details of the explosives referred to are as follow :— Dy nob el No. 2, consisting of the following mixture :— Parts by weight. Ingredients. Not more Not less than than Nitro-glycerine................. 20’5 ... 18 • 5 Nitro-cotton ................... 0’75 ... 0’25 Tri-nitro-toluol, Di-nitro-toluol, and [-together... 3 ... 1 Di-nitro-benzol j Nitrate of ammonium ......... 43’5 ... 40’5 ........... Wood-meal (dried at 190degs. C.) 6 ... 4 Chloride of sodium ............. 31 ... 29 Carbonate of magnesium....... 1 ... — Moisture ..................... 1’5 ... — It is provided that the explosive shall be used only when contained in a case of paper thoroughly water- proofed with a mixture of ceresine and resin; with a detonator or electric detonator of not less strength than that known as No. 6; that the greatest weight of the explosive which may be used in any one shot-hole shall not exceed 24 oz.; and that the explosive shall have been made at the works of Nobel’s Explosives Company Limited, at Ardeer, in the county of Ayr. Four ounces of Dynobel No. 2 gave a swing of 2’46 in. to the ballistic pendulum, compared with a swung of 3-27 in. given by 4oz. of gelignite containing 60 per cent, of nitro- glycerine. Rex Powder, consisting of the following mixture :— Parts by weight. Ingredients. Not moie Not less than than N itro-gly cerine 13 11 Nitrate of ammonium 61 58 Wood-meal (dried atlOOdegs. C.) 8’5 7 ‘ Chloride of sodium 20’5 18’5 Moisture 2’5 — The explosive must be used only when contained in a stout case of paper thoroughly waterproofed with a mixture of ceresine and resin; with a detonator or elec- tric detonator of not less strength than that known as No. 6; the greatest weight of the explosive which may be used in any one shot-hole shall not exceed 20 oz.; and the explosive must have been made at the works of the Cotton Pow’der Company Limited, at Uplees Marshes, near Faversham, in the county of Kent, or at their w'orks near Melling, in the county of Lancaster. Four ounces of Rex Powder gave a swing of 2-61 in. to the ballistic pendulum, compared with a swing of 3-27 in. given by 4 oz. of gelignite containing 60 per cent, of nitro- glycerine. ___________________________ Grimsby Coal Exports. — Returns for the week ending September 3 show that the coal exported from Grimsby was as follow:—Foreign: To Esbjerg, 848 tons; Gefle, 2.067; Karlstad, 290; Banders, 871; Skive, 736; and Svaneke. 221 tons. Coastwise : To Dagenham, 1,690 tons; making a total of 5,033 tons foreign, and 1.690 tons coastwise, against 23,006 tons foreign, and 32 tons coastwise during the corresponding week last year.