June 18, 1915. THE COLLIERY GUARDIAN. 1271 cases. Mr. Rice might well italicise the paragraph referred to, especially that part which stated that “Apparently a condition of super-dusting was produced which in four tests out of five prevented an explosion from starting.” That principle had now been separately demonstrated by experiments in America, Belgium, and Austria, and it had always followed a priori, from the commonest chemical law. The experiments also showed that it required more force to arrest the com- bustion than to start it, and that, on the other hand, 1 lb. of dust distributed through 500 cu. ft. of air was sufficient to propagate the explosion after it had started, all of which was consistent with theory and common sense alike. Such harmony encouraged one to rely with some confidence on other results of the series. He thought that Mr. Rice had carried the stone dust argu- ment another distinct step forward—first, by again insisting that watering of coal dust by ordinary means could never-be efficient; and secondly, by pointing out the hygroscopic capacity of stone dust, especially lime- stone. Sir William Garforth would find that to be an additional weapon in his armoury, and one that would have an immense power with thinking men. That hygroscopic capacity of stone dust had not occurred to most of them, although it certainly ought to have done so. If limestone dust could, as Mr. Rice implied, be also made to part with carbon dioxide during the initial stages of an explosion, that would be a further point in favour of the stone dust theory wherever limestone was available. He (Mr. Halbaum) did not, however, quite see how Mr. Rice had arrived at the view that “ Sample 1 indicates that the heat of the violent start- ing explosion expelled some carbon dioxide from the limestone dust.” The amount (18 per cent.) of carbon —the Bruceton mine had served admirably; but for the arduous investigation of the phenomena of pure coal dust explosions, so badly needed and yet barely begun at any of the experimental stations, the writer believed that a surface gallery of as simple construction as possible would be found to be necessary. Boring and Drilling on Oilfields. This closed the discussion on Mr. Rice’s paper, and Dr. Paul Dvorkovitz’s paper on “ Boring and Drilling on Oilfields,” was proceeded with (see Colliery Guardian, June 11, 1915, p. 1234). Sir William Garforth moved a vote of thanks to the. author, which was carried by "acclamation. Prof. Henry Louis (Newcastle-on-Tyne) wished the author to explain something with regard to his rotary drilling which puzzled him altogether. He stated that the objection to the rotary system of drilling was that it prevented information being obtained as to the nature of the strata passed through, whereas during the last quarter of a century he (Prof. Louis) had been in the habit of employing that system when he wanted such information. Sir William Garforth said he could give an instance where a matter of .£100,000 was lost through not being able to get that information. Prof..J. Cadman thought the author was referring to a hydraulic rotary system, in which mud was used for water flush. In that case there were certain difficulties vote of thanks to the Warwickshire Coal Co. for their kind permission to visit their new sinkings at Keresley, which was carried, said it was an example of one of the newest methods of sinking, and it was gratifying to find that there, as in practically every other case in this country, people who were doing any new work were willing to give the members of the Institution of Mining Engineers an opportunity of seeing it. Mr. Hugh Johnstone (Birmingham), in seconding, said the work was a singularly good example of successful sinking. On the motion of Prof. J. Cadman, seconded by Mr. W. H. Hepplewhite, a vote of thanks was accorded to Mr. H. C. Peake and Sir Wm. Garforth for their conduct in the chair. COAL-SHIPPING PLANT AT PORT TALBOT. The coal-shipping facilities at Port Talbot, South Wales, have quite recently been greatly increased by the introduction of a very interesting installation, which is illustrated in the accompanying engravings. This plant, designed, manufactured and erected by Messrs. Fraser and Chalmers Limited, of Erith, Kent, to the order of the Port Talbot Railway and Docks Com- pany, comprises an electric truck tippler, which dis- 246 O____________________________________________________________________________________________________________j General Arrangement of Conveyor, with Movable Tower for Loading Boats, Port Taibot. dioxide was certainly suggestive, but if any of this had been contributed by the limestone, the oxygen content in any ultimate analysis of the final atmosphere would have been greater than that of the original atmosphere, and the table did not appear to justify that assumption. Dr. R. V. Wheeler (Home Office Experimental Station, Eskmeals) wrote that it was impossible to read Mr. Rice’s account of the preparations that had been made for investigating coal dust explosions without admiration for their thoroughness. At the same time, there must be in some minds doubt as to the wisdom of such elaborate preparations, involving the adjustment of many accurate scientific instruments, for work in a gallery the nature of which might not lend itself to experiments of scientific accuracy. Irregularities in the surface of the walls of the gallery had been shown by the experiments at Altofts to have a great influence on the character of coal dust explosions. The great force developed in the Altofts gallery when it was set with props and bars was remarkable when compared with the slowly moving inflammation produced when the gallery was clear of all obstructions; whilst the effect of con- stricting rings, which reduced the diameter of the gallery by 1ft. at but two or three points 100 ft. apart, was startling. It was to be feared that the many irregularities of surface that existed in the Bruceton experimental mine would so complicate the records (of pressure, for example) as to render them unintelligible. For the work that had already been done — that of educating the mining public of America in the dangers of coal dust and of obtaining quickly by empirical experi- ments some means of lessening the danger of explosions in getting information. He offered that as a possible explanation, in answer to Prof. Louis’s query. Mr. William Calder (Blackheath), in a written com- munication, said he agreed with the author’s statement with regard to 'the more extended use of the rotary water flush tool, which was undoubtedly the quickest system of deep well drilling so far used, but he pointed out that the system could not be used without great risk in territories where oil was being extracted from several horizons simultaneously. The author’s remarks with regard to flooding touched on a detail of oil well engineering which was one of the most important. That danger, however, could be readily and quickly avoided if drastic measures were taken to compel careless and unscrupulous operators to isolate, by cementing or other means, all feeders before the oil zone was reached. In cases where the wells were beyond remedy, the complete withdrawal of all well pipe, and the well plugged as the pipe was withdrawn, should be rigorously enforced. The work in progress should be under the supervision of a committee composed of operators interested in the adjoining properties. No discussion took place on the remaining papers. On the chair being re-occupied by Mr. H. C. Peake, a vote of thanks to' the Geological Society was carried, on the motion of Mr. S. Mavor (Glasgow), seconded by Mr. John Ashworth (Manchester). Mr. Mavor hoped that at some not very remote date the institution would have a home of its own in London, especially now that it had received a royal charter. Prof. Henry Louis (Newcastle-on-Tyne), in moving a charges the coal from trucks through end doors into an underground hopper. This hopper, which is sufficiently large to take the contents of three trucks when necessary, is fitted with a valve to regulate the flow of the coal to the belt. This belt carries the coal and discharges it by means of a chute fitted with a valve to either one or other of the two con- veyors running parallel to the quay front or direct to the travelling tower, when the tower is placed in this posi- tion. The two belts are parallel to the quay, and each of them is provided with a travelling tripper, which can discharge the coal at any point along the run of the travelling tower. This tower carries another belt con- veyor, which discharges by means of a chute to the steamer’s hold. It will be seen by this arrangement that it is possible to discharge coal from a fixed tippler to a steamer at any point along the front of 400 ft. It will be obvious that such an arrangement as this effects a considerable saving, as the sidings, turntables, weighing machines, &c., can be arranged as for a fixed plant, whilst the discharge of the coal can take place at any point for a distance of 400 ft. The travelling tower is moved along by a 10-horse power motor, and travels at a speed of 40 ft. per minute. Any size of steamer can be dealt with, as the conveyor on the travelling tower is hinged and the chute also is hinged, so that it can be placed in any position to accommodate steamers of all sizes. The capacity of the plant is only regulated by the