December 29, 1916. 1265 ______ .. THE COLLIERY GUARDIAN. ___________________________________________________________________________ other hand, in cases like P" where there is a larger pro- portion of compressive stress, the calculated value is somewhat greater, and failure occurs by cracks appear- ing on the outer edges EF of the ribs. In any case it is possible, by making use of the above expressions, to calculate the load necessary to fracture the casting when the position of the load line is known: if the value assumed for in tension be 10 tons per Je sq. in. the resulting loads will not be very far Fig. 3.—Distribution of Stress. < K • qa" rh SECTION THRO’Of -21”------ « J||:t» W3 from the true values. The distribution of the stress throughout the section in the case of each of the loads P', P", P'" is indicated on fig. 3. _________________________ COAL TRADE IN SOUTH AFRICA IN 1916. The coal trade of South Africa has undergone a wonderful change for the better during 1916, especially in the Natal and Transvaal Provinces, and to all appearances the improvement will continue for some time. The year commenced under very unfavourable auspices, owing to the chronic scarcity of empty trucks. It is estimated that in the Transvaal alone the collieries from this cause lost sales in January to the extent of 84,200 tons. What made matters worse was the fact that several shipping lines decided to abolish the Suez Canal route in favour of the Cape route, so that the demand for bunker coal was rapidly increasing at the Cape and Natal. The price of Transvaal bunker coal at the Cape was not increased, but at Durban it went up a shilling per ton and has remained at that figure ever since, the output both in the Transvaal and Natal having now attained record proportions In the Transvaal quite 100,000 tons has been added to the monthly output, and in Natal well over 50,000 tons per month, so that in both Provinces the output of coal in 1916 will easily constitute a record. During the first six months of the year there was an increasing demand both for Transvaal and Natal coal, but as the bulk of the output had been sold forward on contract there was no noticeable change in the average pit top selling price, which in the Transvaal was 4s. 4d. per ton and in Natal 7s. 3d. per ton at the mine. Before the existing railway locomotive contracts expired at the end of June, the Transvaal Coal Owners’ Association arrived at the conclusion that under existing circum- stances it was necessary that better prices should be demanded for the next contract with the railway. The railway at first refused to pay an enhanced price for the new contracts, and immediately approached the non- associated collieries with the object of placing, . if possible, the whole of the locomotive contracts outside the Transvaal Coal Owners’ Association. Several of the outside collieries immediately took steps to increase the output in order to comply with the request of the railway, with the result that a fair slice of the locomotive contracts was placed with the non-associated concerns. The railway, however, being unable to obtain the whole of its locomotive coal from the non-associated collieries, eventually compromised with the Coal Owners’ Associa- tion by taking the balance from them at an advance of about 6d. per ton. After June selling prices were also raised in other directions, with the result that at the collieries in the Transvaal the pit top prices advanced from 4s. 4d. to 4s. 7d. per ton on the average, a higher price than had prevailed at any time during the previous five years. Another remarkable event was the sudden increase of the railway rate to all the ports of 6s. per ton on bunker coal in June and the abolition of the rebate on export coal. This increase made the railway rate on bunker coal 12s. Id. per ton from Wit bank to Delagoa Bay and 20s. per ton to Capetown, whilst from Hatting Spruit, Natal, to the Point, Durban, the rate became 12s. per ton. This increase on bunker coal railway rate is expected to put half a million sterling extra on the railway receipts for the year. Fortunately this extra impost does not seem to have checked in any way the demand for bunker coal, which has continued brisk throughout the year at slightly higher prices f.o.r. at Capetown and Durban. The output of the Orange Free State will constitute a record, at an advance of a few pence per ton in pit top selling price, in sympathy with the other Provinces. The coal, however, being unsuited for bunkering purposes, has not shared in the full improve- ment. The coal trade of the Cape Province has shown little change during the year, either in output or selling price. Attention has again been drawn to the fissure coals of the Karroo, but so far they have not proved to be of any economic value. ______________ LIST OF APPROVED SAFETY LAMPS. The Safety Lamps Order, dated November 16, 1916, gives the following list of safety lamps now permitted to be used in mines :— Part 1. Flame Safety Lamps Approved for General Use. Submitted for test by 1. Ackroyd and Best Ltd. ... 2. Best's Safety Lamps Ltd. 3. Joseph Cooke and Son ... 4. Cremer Lamp and Engi- neering Co. Ltd. 5. John Davis and Son (Derby) Ltd. 6. Richard Evans & Co. Ltd. 7. Richard Johnson, Clap- ham and Morris Ltd. 8. James Laidler and Sons 9. M. Lowrance and ion ... 10. John Mills and Sons ... 11. J. H. Naylor ........... 12 Paterson and Co........ 13. Protector Lamp and Lighting Co. Ltd. 14. J. H. Rothwell and Co. .. 1’. W. E. Teale and Co. Ltd. 16. E. Thomas and Williams Ltd. 17. Wolf Safety Lamp Co. ... Part II.—continued. Submitted for test by 9. J. H. Naylor .......... 10. Patterson and Co...... 11. Protector Lamp and Lighting Co. Ltd. 12. J. H. Rothwell and Co. ... 13. W. E. Teale a d Co. Ltd. Name of lamp. Bifold Burner Marsaut (for officials). Marsaut “A 1" and “ B 2." Marsaut “ E." or “E. 1." Marsaut “Fl." Naylor’s Protector, Types “ G 1," “Hl," and “II." Marsaut “ K 1." Marsaut “ L 1." Mueseler “K 1." Marsaut “KB 1." Mueseler “KB 1." Types A 2, A 4, and B 2. Type D 1. Types B 5 and B 6. Type B 8. Types D 1 and D 2. “ Prestwich Patent Pro- tector, A." “A1,"“A2," “Cl," “C2." Standard Bonnetted Mar- saut, No. 4 A. Teale's Protector, No. 1A and No. 2 A. Mueseler or Thornburry, No. 6 A. Cambrian No. 1 A. Cambrian Improved Fire- man’s, No. 21. Cambrian No. 7. (b) Porch and Roadway Lamps, to be Used only within Certain Limits. 14. E. Thomas and Williams Ltd. Name of lamp. Hailwood, Nos. 01 and 01 S. Hailwood, No. 02. Hailwood, Nos. 0 12 and B1. HailwooH, Nos. UO1 & UB 4. Best's “ Excelsior," Nos. 1, 2, 3 and 4. Best's “ Gauzeless," No. 1. J.C.B., Nos. 19 and 22. J.C.B., No. 19 F. Cremer, No. 1 ’. Cremer Marsaut, No. 12. *Patterson, No. 12. tWolf, No. 7. No. 1, Davis-Marsic. Davis-Mars try. Davis-Marstryn. No.. 2, Davis-Kirkby. No. 1B, Da vis-Mar sty-Loose. No. 5, Davis-Thornley. No. 8, Davis-Thornburry. Davis-Marstif. Hay dock Colliery Pattern. Nos. 1 and 2. Nos. 4 and 4 A Deflector. No. 5 J.C.M. No^. 1,1 A and 2. Hickleton Main Colliery , Pattern (H M.C.). Monk Bretton Colliery ________ Bifold Burner Marsaut. Marsaut(< A " and “ C." Marsaut “B " and “ D." Naylor's Protector, Types “G," “H," and “I." Marsaut“ F " Lamp. Marsaut“ K." Marsaut “ L." • Mueseler “ K." Marsaut “ K.B." Mueseler “ K. B." Types A 1 and A 3. Type B 1. Types B 3 and B 4. Type B 7. Prestwich Patent Protector. No. 176, Oil. Prestwich Patent Protector O 8 “A” “ B,"“C," “D," and “E." “ A 3," “ B 3," S( C 3," “ D 3," and “ E 3." Protector, No. 1. Protector, No. 2. Standard Bonnetted Mar- saut, No. 4. Protector, No. 3 and Standard. Deflector Marsaut, No. 5. Mueseler or Thornburry, No. 6. Cambrian, Nos. 1 and 3. Cambrian Deflector, No. 15. Cambrian, No. 9. W olf-Patter son. Part II. Flame Safety Lamps Approved for Special Purposes. Submitted for test by 1. Ackroyd and Best Ltd. ... 2. Best's Safety Lamps Ltd. 3. Joseph Cooke and Son ... 4. Cremer Lamp and Engi- neering Co. Ltd. 5. John Davis and Son (Derby) Ltd. (a) For Use by Officials Only. 6. Richard Johnson, Clap- ham and Morris Ltd. 7. James Laidler and Sons... 8. John Mills and Sons ... Name of lamp. Hailwood, No. 01 A. Hailwood, Nos. 06 and F 1. Beat’s “ Gauzeless," No. 1 A. J.C.B., Nos. 19 A, 19 FA, and 22 A. J.C.B., No. 27 A. No. 11 A. No. 11, Davis-Beacatorh. No. 3, Davis-Boss. No. 6, Davis-Alumthorn. No. 7, Davis-Diabl. No. 3 C, Davis-Bossgy. No. 9, Davis-Graybeard. No. 10, Davis-Gry. No. 3 and No. 6. No. 2 A. ‘ J M.S." N. 2J.MS-" ”N? No. 2. No. 3. * This lamp was manufactured by the late Wolf Safety L imp Company Limited, Leeds, and by the late Messrs. Baxendale and Co., Manchester. t Tti is lamp was manufactured by the late Wolf Safety Lamp Company Limited, Leeds. Submitted for test by Name of Lamp. 1. Ackroyd and Best Ltd. ... Porch Safety Lamp, No. (010) P. 2. John Davis and Son Davis-Porcas. (Derby) Ltd. 3. Richard Johnson, Clapham No. 7, Deflector Roadway. and Morris Ltd. 4. J. H. Naylor, Wigan ... Roadways, Nos. 1 and 2. Part III. Electric Safety Lamps Approved for General Use. Submitted for test by 1. Bristol Electric Safety Lamp Works. 2. British Accumulator Co. Ltd. 3. “Ceag" Miners’ Supply Co. Ltd. 4. John Davis and Son (Derby) Ltd. 5. General Electric Co. Ltd. 6. W. E. Gray............ 7. Manley and Sandy Ltd. .. 8. John Mills and Sons ... 9. Oldham and Son ....... 10. Pearson's Electric Miners' Lamp Co. Ltd. 11. Rothwell and Co. j The Thomson Co. )..... 12. J. H. Rothwell and Co. ... 13. W. E. Teale and Co. Ltd. 14. Tudor Accumulator Co. Ltd. 15. Wolf Safety Lamp Co. .. 16. Worsnop and Co. Ltd. .. Name of lamp. Bristol, Type B.T. 4 V. B.A.C. “Ceag." Davis-Edison Accumulator. Turquand-Kingsway. Kingsway. Gray-Sus s m ann, Nos. 3 and 4. Manley and Sandy (M. & S.). Joel-Fors, Type 403 M. Oldham. Pearson. Th omson-Roth well. Rothwell No. 3. No. 1 Electric. Varta. Wolf, Alkaline. Wolf, Lead. Wolf, No. 2. Worsnop. Part IV. Electric Safety Lamps Approved for Use by Officials. or for Special Submitted for test by 1. Bristol Electric Safety Lamp Works. 2. Float Electric Co. Ltd. ... 3. John Mills and Sons ... 4. Oldham and Son ... ... 5. Pearson’s Electric Miners' Lamp Co. Ltd. 6. Tudor Accumulator Co. Ltd. 7. Wolf Safety Lamp Co. ... Purposes only Name of lamp. Bristol, Type B.R. 4 V. Float Patent. Joel-Fors Electric Inspec- tion Lamp, Type 303 C. Joel-Fors Electric Hand Lamp, Type 403 H. Oldham “ Emergency." <( Oldham" Shaft and Road- way, Types “A ’’ and “ B." Officials’ Pocket Lamp.* Varta, Type 2Et4. Wolf Rescue, No. 2. * This lamp is only to be used in conjunction with another safety lamp of approved type. ____________________________ French School of Mines Improvement Committee. — The French President has appointed a committee, of the follow- ing gentlemen, to consider the improvement of the School of Mines MM. Boudenoot (senator), Siegfried (deputy), Robeillard (Paris municipal councillor), De Ribes-Christofle (Paris Chamber of Commerce), Carnot (president, Paris Gas Company), Lebrun (Government mining engineer and deputy), Reumaux (general manager of the Lens Mines), Leon Levy (manager, Chatiilon-Commentry Iron Works), Gruner (vice-president of Central Mining Committee), Paraf (manager, Pontgibaud Mines), Mauris (manager, Paris, Lyons and Mediterranean Rly.), Sartiaux (chi^ engineer, Nord Railway), Ghesquiere (president, Syndic ad Chamber of Metals), Mercier (president, Soc. Acieriee de France), Savy (vice-president, Boilermakers and Foundrymen’s Syndicate), and De Fontviolant (chief engineer, Fives-Lille Company). Spain Seeking a Coal Substitute.—The fuel question has become of such importance of. Inte in Spain that practical experiments are being made by which various materials hitherto considered of small value may be employed to a certain extent as a substitute for coal. For many years in the rice-raising provinces of Spain rice husks have been utilised as fuel for heating boilers in the rice mills, but this practice does not completely exhaust the combustible matter of the husk. The plan is now being tried of farming the husks into briquettes by mixing with tar and submitting to hydraulic pressure. The husks at present are sold in sacks of about 44 1b., casting from 1c. to 4c. a sack, according to season. As even large quantities yield comparatively little heat, their use in natural form is expensive. Another briquette is now being made from inferior qualities of lignite. Even lignite dust and waste which were formerly discarded and useless and an encumbrance are treated to expel latent volatile matter, and then petroleum residues or similar binding material are added.