members; that they may be the means of leading to the reading of papers on some of the subjects to which I have referred; and that interesting and instructive discussions may be thereby encouraged and stimulated. I have no hesitation in stating that the Midland Institute of Mining, Civil and Mechanical Engineers includes among its members as many clever practical engineers as can be found in either this or any other country, and that if conditions and opportunities are afforded to them for the exercise of their practical knowledge they are bound to come out at the top of the tree. I trust that any members who have any machinery of general interest working at their collieries, will bring it before the notice of the members in the form of a paper, so that we may be enabled to meet together frequently for the interchange of ideas and friendly discussion thereon, and that all may thereby mutually benefit from each other's experience. Mr. JOHN GERRARD proposed a vote of thanks to Mr. Nash for his address. He had heard it read with great pleasure, and he hoped that Mr. Nash would have a very happy and successful year of office, coupled with plenty of papers and long and interesting discussions. Mr. H. ST. J. DURNFORD seconded the resolution, which was carried unanimously. DISCUSSION OF MR. THOMAS MOODIE'S PAPER ON "THE WORKING OF CONTIGUOUS, OR NEARLY CONTIGUOUS, SEAMS OF COAL."* The PRESIDENT (Mr. H. B. NASH) said that when there were two nearly contiguous seams of coal, which could not be worked together, if they worked the top seam first it made a bad roof, and if they worked the bottom seam first, they damaged the top seam so that it was not worth working, unless it was dealt with in a very careful manner in the way of packing. One point to be considered in working contiguous seams, where both are worth working and are of good quality, was the length of time that * Trans. Inst. M.E., 1902, vol. xxiii., page 283; and vol. xxiv., page 116. should elapse between the working of the one and the working of the other, because, in taking out the bottom seam, the manner of working it would materially affect the top one, in fact the top seam might prove unworkable, if it were crushed or broken by the working of the lower seam. But if the top seam were worked first, a little in advance of the lower seam, it might be wrought economically. The angle of inclination was also a factor in determining the order of working contiguous seams. Mr. GERRARD asked whether there were any cases in Yorkshire where the top part of a seam was worked in advance of the lower section. The PRESIDENT (Mr. H. B. Nash) stated that at Woolley colliery, it was desirable to work the bottom seam first, and that the working of the other should follow at not too great a distance. The face in the bottom seam should not be driven more than 150 feet in front of the face in the top seam. Mr. G. H. AsпWIN said that for twelve years he had worked three nearly contiguous seams. The top seam (called the Twoyards) was 5 feet thick; there was about 3 feet of strata between that and the Ryder seam, 6 feet thick; below was about 4 feet of good coal, which they did not get, except the bottom part of it; and below was the Slate coal, 3 feet thick. These seams lay at angles varying from 12 to 17 degrees. The seams were worked on the longwall system. The bottom seam was taken out first; then the Ryder seam, 75 feet behind; and lastly the Two-yards seam, 45 feet farther behind. At a neighbouring colliery, an unsuccessful attempt was made to work the top seam first. There were three collieries in Yorkshire working three contiguous seams, one working four seams, and two or three collieries were working two seams. In every instance, the lower seam was the first one to be worked. seams Mr. W. H. PICKERING remembered a colliery where two were worked simultaneously. The bottom seam was the first one to be worked, about 36 feet in advance of the workings in the top seam. DISCUSSION OF MR. W. E. GARFORTH'S PAPER ON "THE APPLICATION OF COAL-CUTTING MACHINES TO DEEP MINING."* Mr. G. BLAKE WALKER said that coal-cutting in the Florence colliery, North Staffordshire, in a seam about 1,800 feet deep and 5 or 6 feet thick was successful. The pressure was exceedingly great, when the coal was worked in the ordinary way. The timber snapped frequently, and the coal was very small when worked by hand-labour; whereas, with the rapid movement of the machine-face, much larger coal was obtained, and the timber did not break to anything like the same extent. At the adjoining Fenton colliery, two coal-cutting machines were doing efficient work at a great depth. His own experience with regard to using coal-cutting machines at great depths had been rather in the contrary direction. In the Whinmoor seam, where he was working coal-cutters, he now used only one machine, probably because it was not worth the trouble and expense of taking in another coal-cutting machine. The coal was tender at great depths, and very much more likely to break than where the weight was less. Mr. H. ST. J. DURNFORD stated that his experiments with coal-cutting machines in the Silkstone seam had been more or less a failure. He commenced with a machine driven by an electric motor, and holed to a depth of 42 feet, but it never managed to hole more than 90 feet in a shift. He then tried a large wheel, to hole to a depth of 5 feet, driven by a larger motor, making the cutting-wheel run about 60 revolutions per minute. The holing was made in hard coal, he had seen a continuous flow of flame from the rim of the cutting-wheel, eventually there was a small explosion, and the use of the machine was forthwith discontinued. He had not the slightest doubt that this explosion was caused by coal-dust (as there was no gas) ignited by the sparks produced by the great speed of the cutting-wheel. In their seam, 1,800 feet deep, the roof was not particularly good, and the floor was decidedly bad; but there was no particular reason why he should not try again. He did not think that, in a seam of coal where the getting price was 1s. 9d. per ton, there was much profit to be gained by getting coal by machinery, but * Trans. Inst. M. E., 1902, vol. xxiii., page 312. there was undoubtedly a large gain in the percentage of round The coal-cutters in the Warrenhouse seam were cutting coal. 150 to 180 feet in a shift without difficulty. Mr. J. GERRARD asked whether the sparks proceeded from the cutting-wheel or from the electric motor. Mr. St. J. DURNFORD replied that there was a continuous stream of sparks from the rim of the cutting-wheel. Mr. C. SNOW said that he had only had experience of one machine working in a seam 1,620 feet deep, 7 feet thick, with a bound roof. When getting the coal by hand, the roof was so good that, excepting for the requirements of the Coal-mines Regulation Act, no props would have been set; there were no breaks in the roof. So soon as the machine began to work, the roof began to break, and he asked whether that was due to the more rapid advance of the working-face. Eventually the coalcutting machine broke down, and they reverted to hand-cutting; and they had not been at work a month, before the old conditions of roof again prevailed. The machine was repaired, and on resuming work, the roof was again broken. The further discussion was adjourned. THE MINING INSTITUTE OF SCOTLAND. GENERAL MEETING, HELD IN THE HALL OF THE INSTITUTE, HAMILTON, DECEMBER 11TH, 1902. MR. HENRY AITKEN, PRESIDENT, IN THE CHAIR. The minutes of the last General Meeting were read and confirmed. The following gentlemen were elected : MEMBERS Mr. HARRY D. D. BARMAN, Airdrie Ironworks, Airdrie. Mr. RICHARD E. M. BATHGATE, 20, Charing Cross Mansions, Glasgow. Mr. DUNCAN CAMPBELL, Greenfield Foundry, Hamilton. Mr. JOHN GRAY, Morningside Colliery, Newmains. Mr. DAVID LIVINGSTONE, Woodmuir Colliery, West Calder. Mr. CHARLES LATHAM, The University, Glasgow. STUDENT Mr. GEORGE HUNTER, Tinto View Terrace, Coalburn. DISCUSSION OF MR. JAMES BAIRD'S "DESCRIPTION OF UNDERGROUND HAULAGE AT MOSSBLOWN COLLIERY, AYRSHIRE."* Mr. JAMES BAIRD wrote that, since the last meeting of the members, he had renewed the rope of No. 1 Pit haulage-level, and consequently he was now in a position to answer Mr. Mowat's question more fully as to the difficulty of putting a rope on to the horizontal Clifton wheel and preventing the rope from becoming slack and falling during the operation. He could at once state that he did not experience the difficulty mentioned by Mr. Mowat. The modus operandi was as follows:-The new rope, 5,400 feet long, was taken along the haulage-road, on a reel, and placed on the empty roadway about 50 feet from the central station. The * Trans. Inst. M.E., 1902, vol xxiii., page 155; and vol. xxiv., page 115. |