April 14, 1916. THE COLLIERY GUARDIAN. 703 Debris was tipped and water discharged at the upper level. When these materials were being drawn, the steel doors stood open and effectively fenced two sides of the opening into the shaft. Wooden spars, fixed to the corner posts, provided the necessary protection on the other two sides. The upper doom were kept closed until the kettle or water barrel approached the surface. By observing a mark on the winding rope, the pithead- man knew when to open the doors. These were there- after closd, and the debris or water discharged into the shoot. The doors were again opened for the kettle or barrel to be lowered into the shaft, and closed again as soon as it had passed clear. Each stage of the sinking and lining was carried out as described. The bottom 4 ft. to 6 ft. of each length of brickwork was built solid against the sides, and was 14 in. thick. The remainder was carried up 9 in. thick, except where a junction was made with the brickwork above. There, the last three or four courses were from 9 in. to 44 iij. thick, depending on the hardness of the strata forming the seat to the brickwork above, and the amount of hewing necessary. Lt was only when about to commence each length of brickwork, and at intervals during the building of it, that the centre plumb line was run down. The temporary fixture for the plumb line had to be abandoned when the kettle strike was erected. The wire was then passed over a small pulley mounted on a piece of batten, hinged opposite one side and at the level of the steel doors. On the doors being opened, the pulley could be swung over into position, so that the wire passing over it was exactly in the centre of the shaft. Water rings, to catch water finding its way down through the ashes behind the lining ,or trickling down the face of the brickwork, were formed at various levels in the shaft. Doorhead Lintels. In the course of the sinking the shaft passed through three seams of coal worked from the old pit. Although it was not intended to wind coal from these levels, con- nection, was made at each seam. The brick lining at each of these entrances to the shaft was built 18 in. thick, and at each an opening 9 ft. wide and about 6 ft. high was formed, in order to provide access to either cage when desired. The brickwork above each opening was carried on a strong channel section cast iron lintel, 12 in. broad by 12 in. deep, and curved to the circle of the shaft. The -Entel was steadied and strengthened by a stout timber post set underneath its centre. The bottom of the post rested on a timber sole, curved to the circle of the shaft, and the top was fitted into a pocket cast on the underside of the lintel. No special provision had to be' made for ventilation. As already mentioned, the shaft made connection with three working seams, the upper one being only 234 ft. from the surface. Between it and the lower seam a blind pit had, at an earlier period, been put up for ventilation purposes, in the position of the new shaft, and this simplified the ventilation. The shaft was lit up by electric light. The tools used by the sinkers were similar to those required for the sinking of a rectangular shaft. Having regard to the times, and the need for an increased output of coal, sinking was stopped when the shaft reached a total depth of 426 ft. from the surface, there being no intention in the meantime to wind from a lower level than 330 ft. At that level the pit went down on a back mine, which had previously been driven across a fault to, and a short distance beyond, the site of the shaft. Before lining the shaft at this point, the sides of the mine were widened out to the width of the proposed landing for a distance of about 20 ft. on either side of the shaft, so as to avoid the possibility of damage to the brickwork from blasting operations. The brick- ing seat was 7 ft. below the level of the landing, and from that point, up to the level of the door-heads, the lining was built 18 in. thick. An opening, 9 ft. wide and 9 ft. high, was formed on either side of the shaft to the underside of a cast iron lintel carrying the brickwork above. This mine was in line with the centre one of three parallel longwall dook-roads, each 50 ft. apart, which had been driven from the old pit, in a virgin seam, for a distance of well over a mile, in order-to develop a large area of coal to be won by the new shaft. It may be remarked, in passing, that the 50 yd. wall was cut by a 5 ft. disc coal cutter, and that the rate of travel of the face averaged 400 yds. per annum. During the sinking operations, the permanent winding engines had been erected. These consist of a pair of coupled engines, with cylinders 22 in. in diameter by 5 ft. stroke, and a drum of 12 ft. 3 in. in diameter, work- ing on a boiler pressure of 65 lb. per sq. in. The pit head scaffold had also been erected and connected with the screening plant. The forming of the pit bottom, and the putting in of the permanent fittings of the shaft, ■were therefore all that was required to’equip the shaft for drawing coal. The cages have been designed so as to obtain .a strong light structure, easily repaired when damaged, and to coliform to the requirements of the Coal Mines Act. The clearance between the cages is 6 in., when these are in running position in the shaft. . The commoner practice is to give greater clearance, and also to provide four guide ropes to each cage. In such cases the buffer ropes are closer together than they would otherwise be placed. Such an arrangement, however, is not essential to secure safe and satisfactory travel of the cages in the shaft. What has to be guarded against is a twist, rather than a swing, of the cages when running. Therefore, the wider the guide ropes and buffer ropes, respectively, are apart, the less tendency there will be for the cage to twist out into the shaft. There is, however, a limit to the distance that the buffer ropes can be put apart with safety. If placed too near to the end of the cage, there would always be the possibility of a longitudinal swing of the cage, allowing the buffer rope to get round the end of it, , and thereby out of action. The curved ___________________________ ________ ________________________________________________________________________________________________________________________________ square and 9 in. deep, provided with a door at one side, and a lug at each of the four corners for the attachment of the suspension chains. When the concrete backing was being filled in, the box was lowered, and the front or door side of it rested on the top of the brickwork. The front chains were then detached, the door taken out, and the back end of the box raised gradually until the contents slid out into position behind the brickwork. Bricking Scaffold. _____________________________ The bricking scaffold was 13 ft. in diameter. The body was of 9 in. by 3 in. white pine planks, bolted to 6 in. square oak beams with f.in. bolts. On two of its sides a 2 ft. segment was made to fold in on strong iron hinges, well secured to the main portion. These wings were made from 12 in. by 3 in. red pine planks, bolted across 6 in. square pieces of oak, and were strengthened in the centre by a 9 in. by in. white pine doubling underneath. The scaffold was suspended by four | in. shortdink chains, 12| ft. long, attached by muzzle and pin to eye-bolts passing down through the outside oak beams. These eye-bolts were fixed diametrically oppo- site, and were 7 ft. apart on the line of the beam, and 9 ft. apart across the same. The scaffold was provided with four strong slip bolts, each Sin. square and 24 ft. long, sliding in 3 in. by J in. keepers, the outer of which was also bolted down through the oak beam. The bolts, when fully extended, projected. 6| in. beyond the edge of the scaffold. Between the outer and the inner keeper, a Jin. set pin was screwed into the body of the bolt, in order to adjust the travel, and to prevent it from falling out when the scaffold'was tilted or hung up in the shaft. Another set pin, screwed down through the inner keeper, fixed the bolt in an extended or withdrawn position, as required. A strong muzzle was fixed to the edge of the scaffold, midway between the wings, by which, with the wings folded, it could be hung up on edge close in against the sides of the shaft. The scaffold, when not required, was lifted out and laid aside on the surface up to the time that the mouth of the shaft was covered over. On the completion of the surface foundation block, •sinking was resumed. Plumb-strings, hung from the face of the brickwork above, made it easy for measure- ments to be taken to ensure that the sinking was circular, and to the proper size. The excavation was gradually widened out to 17 ft. in diameter, and con- tinued at that size until the sinking had reached the bottom of the surface clay, at a depth of 46 ft. from the surface, and passed into soft fireclay, 5 ft. thick, lying on the top of sandstone rock. This portion of the sink- ing was temporarily supported by rings and backing deals, as previously described. The excavation was reduced to 154 ft. in diameter from the bottom of the clay, and continued at that size until about 6 ft. above where it was decided to found the next bricking seat, when the shaft was widened out and sunk 16 ft. in diameter, until a bed of fireclay, 37 ft. below the brick- ing seat above, was reached. Bricking Seat in Rock. A sump hole having been made, the centre plumb- line was run down, and bricking commenced in the same way as for the previous stage. As the inclination of the strata was slight, no special preparation was required for the seat. The brickwork was brought up from the low _____________________________ side, and levelled all round. The first 6 ft. was made 14 in. thick, and was built solid against tihe metals; from that point upwards the lining was 9 in. thick. As the brickwork rose, and until the bottom of the surface clay was reached, ashes were packed in behind. Thereafter, cement concrete formed the backing for the completion .of the stage. As before, and in each successive stage, the timber and rings temporarily supporting the sides were with- drawn as the brickwork progressed. When the latter approached the bottom of the upper length, the whole of its seat was cut away, and the brickwork joined up with 9 in. work. No slipping of the upper length was observed. A further length of 30 ft. having been sunk and lined, sinking was temporarily stopped until the perma- nent pithead frame and pulleys had been erected, a steam winch fitted up to replace the crane, and a kettle strike placed over the mouth of the shaft. The pit head frame is of timber, 55 ft. high to the centre of the pulleys, in order to provide adequate height for the adoption of double deck cages, if these should at some future date ______________ ______________ be required. The pulleys are 12 ft. in diameter, and are placed 41 ft. apart. The steam winch had 8 in. by 14 in. cylinders, and was geared 44 to 1. The drum was 5 ft. in diameter, and 8| ft. wide. A special patent improved steel wire non-rotating sinking rope, 3 in. in circumference, was used, and a 3-ton detaching hook was provided. Before the kettle strike could be erected, and so long as it was in use, the bricking scaffold, whiA hitherto, as ______________ ______________ previously mentioned, had been swung out and laid down on the surface when not required, had to be hung in the shaft. Kettle Strike. The strike was built centrally over one of the proposed cage spaces in the shaft. Two pitchpine beams, 12 in. broad by 9 in. deep, were laid across the shaft, equidis- tant from the centre, and 5 ft. apart, so as to form the foundation for the structure. Between these, the folded bricking scaffold was lowered on edge, and hung as close as possible to the side of the shaft from a beam resting on the two previously mentioned. Bricks and ashes were filled into the kettle and mortar into boxes, and conveyed on a low bogie to the shaft. ______ ______________ The empty kettle or box, on reaching the surface, was rested on another bogie run into position over the closed doors. It was then detached from the rope, and the bogie withdrawn. The loaded bogie was run in, the load picked up, the empty bogie withdrawn, the doors opened, and the load lowered down the shaft. slippers fitter! on the cage are designed to facilitate, in such a contingency, the return of the rope to its correct position more readily than if a square corner had to be negotiated. The absence of water in any considerable quantity, and of bad ground to any appreciable extent, made the sinking described a simple matter, when compared with many that have been undertaken elsewhere and success- fully carried out. THE PLEXSIM ELECTRIC STILL. The use of the miners ’ electric lamp is simplified by the introduction' of the Plexsim electric still, which facilitates the provision of distilled water for the accumulators. Fig. 1 is an elevation, and fig. 2 is a section showing the action of the still, which is entirely automatic. Fig. 1. Fig. 2. I i Hl The cold water enters at A, where it should be con- trolled by a screw-down water tap, and passes through the pipe B to the outside of the condensing chamber and coil, C and D. After filling the tank and coil, the overflow water passes through the pipe E into the small feed tank G, which is so arranged that there is no loss of heat at this point and no disturbance of the constantly boiling water in the evaporating chamber J. The over- flow water is taken by the pipe F to a suitable waste drain. The heating elements K are mounted on the underside of the evaporating chamber, and when the water is flowing and the current is switched on, the water rapidly boils. The steam given off rises through the cone L, and impinges on the surfaces of the walls and coil in the condensing chamber, where it rapidly condenses, the drops of distilled water falling into the distillate chamber H, from whence it flows through the outlet I into a suitable receptacle. No attention is required; so long as water and electric current are flowing, nothing can go wrong. For economy in working, the flow of the feed water should be so regulated that the temperature of the waste water is about 150degs. Fahr., at which point the still works at its greatest efficiency. All the parts are easily detach- able and accessible, including the heating elements. The still is made by Simplex Conduits Limited, Garrison-lane, Birmingham. Mineral Production of Japan. — According to the official returns, the mineral production of Japan (including Formosa) in 1914 was valued at 153,309,716 yen (1 yen = 2s.), as against 145,848,792 yen in 1913, but these figures do not com- prise the output of the Imperial steel works, valued at about 13 million yen per annum. The production of coal in 1914 was 21,315,962 metric tons, valued at 70,956,121 yen; in 1915 it is estimated that 19,000,000 tons were produced, the decrease in output being attributable to the lessened demand in the Far East, as a result of the war. During the first nine months of 1915, about two million tons were exported, or over one million tons less than in the corresponding period of the preceding year. The following shows the approximate output of the principal mines :—Yubari, 760,000 toms; Iriyema, 530,000 tons; Miike (Mitsui Company), 2,000,000 tons; Mitsui-Tagawa (ditto), 983,000 tons; Onoura, 790,000 tons; Futase (Department of Agriculture and Commerce), 600,000 tons; Yoshinotani (Mitsuibishi), 540,000 tons. The produc- tion of steel has nearly doubled. Exports and Imports of Mining Machinery.—The value of imports and exports of mining machinery during March are given below :—■ March. Jan.-Mar. 1915. 1916. 1915. 1916. £ £ £ £ Imports .......... 3,366 ... 10,237 . 19,223 ... 28,671 Exports .......... 47,032 ... 50,236 ...130,900 ...163,676 These figures are not inclusive of prime movers or electrical machinery. According to destination, the value of exports was as under ;— March. Jan.-Mar. 1915. 1916. ^915. 1916. To— £ £ £ £ Countries in Europe..... 8,799 ... 3,620 ...16,997 ... 12,534 UnitedStatesofAmerica... 16 ... 63 ,. 16 ... 439 Countries in S. America ... 776 .. 1,548 ... 2,774 ... 4,531 British South Africa ... 17,007 ...26,881 ...55,414 . 79,219 ,. East Indies ..... 3,840 ... 3,500 ...12,064 ... 17,592 Australia ............... 1,352 ... 1,760 ... 8,236 ... 8,373 New Zealand __.........___....___ 234 ... 3,424 1,776 ... 4,379 Other countries ......... 15,008 ... 9,440 ...33,623 ... 36,609 Total ............. 47,032 ...50,236 ..130,900 ...163,676 The following shows the value of exports of prime movers other than electrical :— March. Jan.-Mar. 1915. 1916. 1915. 1916. All prime movers (except £ £ £ £ electrical) ........... 600,092...317,530...1,742,007...1,098,306 Rail locomotives ...... 247,535... 74,024... 759,013... 330,487 Pumping ............. 44,886 21,859... 116,671... 119,368 Winding............... 305... 949... 2,497... 2,565