June 6, 1613. THE COLLIERY GUARDIAN. 1189 HADFIELD’S LIMITED. Hadfield’s exhibit of their manufactures is divided into two sections, the larger of which is devoted principally to steel haulage appliances for mines and collieries and the other to stone-breaking and ore- crushing machinery. In the colliery section there are several groups of various types of their well-known steel tub wheels fitted on reeled steel axles by their special method; colliery wheels of all sizes made of Hadfield’s patent “Era” manganese steel and Hadfield’s toughened cast steel; steel haulage rollers and pulleys, some with and some without frames ; a variety of types of rope clips, buffer hoops, pedestals, drawbars for colliery tubs; and other specialities too numerous to mention. Examples may also be seen of Rowbotham’s self-oiling arrangement, applied to both colliery tub wheels and furnace charging barrow wheels. The well-known “Sylat” prop with- drawer is represented with various attachments fitted to prevent props springing-back when the chain block, that runs on the rack bar of the withdrawer, is released preparatory to taking up another length of chain. An automatic tub controller and tub-axle greaser is placed in working position at one end of the stand. There are also two of Hadfield’s steel dust-proof tubs fitted up complete with their steel wheels, axles and pedestals. One of the tubs is constructed with a well bottom, a design which materially increases the capacity, and which renders it eminently suitable for collieries with low seams. The other one is fitted with a wooden underframe. Hadfield’s patent “Era” manganese steel is well represented in both sections of their stand by a miscellaneous array of castings, including furnace charging barrow wheels, single-flanged colliery wheels, edge wheels, grids for coal screens, elevator links, stone- breaker jaws, gyratory crusher mantles, crushing roll shells, and “ Hecla ” disc crusher discs. The smaller portion of the stand is comprised of Hadfield and Jack’s “ Heclon ” rock and ore breaker, Hadfield’s stone breaker, and the “ Hecla ” disc crusher. The Hadfield stone breaker is of the reciprocating jaw type, and embodies several new features. Instead of the body being of cast iron, as is usually the case, it is made of Hadfield’s best cast steel. The third machine, the “ Hecla ” disc crusher, is a new type of crusher altogether. The crushing is performed in a cavity formed of the two “ Era” manganese steel discs which revolve at great speed, one of which oscillates several hundred times a minute. When the product is reduced \ A I • a it - * ■ ' . - # l «r j.sLSL’?,; - r. . ■ , ■ The Exhibit oe Messrs. Hadfield’s Limited. to the proper size, the rapidly revolving discs fling it out into the chute. This prevents all congestion and produces a machine of enormous capacity for its size. It will take rejections, screened or unscreened, from standard crushers and rapidly reduce same, at one operation, to in. size or less, and is the only crusher that successfully reduces wet or dry gravel boulders, mixed with sand, to a smaller product. REAVELL AND CO. Messrs. Reavell and Co., of Ipswich, are exhibiting on their stand some of their mining specialities, and one or two types of compressors. One of their medium size quadruplex compressors is shown direct-coupled to an electric motor, the arrangement being somewhat similar to that shown. The compressor, however, being fitted with a special form of continuous lubrication pump to obviate the necessity of filling the oil-box at regular intervals. This device is fitted with complete filters to clean the oil before it is returned to the oil feeders. This machine is seen in operation and very clearly demonstrates the action of the well-known quadruples compressor. The machine is extremely free keeping the motors, generators and switchgear free from from vibration, which is proved by the fact that it is • dust, &c. There inc Oil tlie at 1 ** actually running at the Exhibition under- a low air running gear, lubrication pump, &c., pressure, and not bolted down to the floor in any greater detail the workin way : but with apparently no tendency to move. A portable rock-drilling plant, consisting of one of Patent Air Hoist. (Messrs. Reavell and Co.) 1 St Messrs. Reavell’s patent axial type of compressor direct coupled to a motor, the whole plant being particularly suited for mining work and for supplying air to one band rock drill, should prove of great interest to all mining engineers. This compressor is delivering its air into a portable type of mining receiver from which the air was taken to various exhibits in the Hall. This axial compressor represents an extremely compact and comparatively inexpensive form of compressor with an extremely simple motion, with only three main working parts and with a continuous system of lubrication, and mining engineers should give careful attention to the use of such plants close up to the coal face. Another exhibit of vital interest to mining engineers is Messrs. Reavell and Co.’s patent air hoist. This hoist is shown in operation, and its use for com- paratively small weights and actually in the mine, was very apparent. The hoist is extremely compact and of the four-cylindei- construction, and the drum itself is driven through epicyclic gearing. It is pneumatically operated and will run with air at any pressure from 20 lb. per square inch up to 80 lb. or 100 lb. per square inch with corresponding lifting powers. The hoist itself is mounted on a substantial pillar which has an adjustable foot by which it is possible to shore it up so as to make it rigid during running. An example of Messrs. Reavell’s now very well-known “ sub-station ” cleaning set is exhibited and is run- ning. This set consists of a small compressor bolted direct on to a motor frame and provided with starter, hose, drum and flexible cable with wall plug. This set is of great use in collieries which are electrically equipped, as it is extremely portable and can be used for There are also on the stand examples of ., ’ which show in parts of the Quadruplex compressor. The wide range of machines in which Messrs. Reavell Quadruples Compressor. (Messrs. Reavell and Co. Portable Rock-drilling Plant. (Messrs. Reavell and Co.) specialise is shown by the exhibition of a very minute compressor, weighing less than 2 lb., this small machine being used for maintaining the pressure in petrol tanks on aircraft. MAVOR AND COULSON LIMITED. A description of Messrs. Mavor and Coulson Limited’s exhibits is necessarily lengthy. It goes without saying that a principal feature of the stand occupied by this well known Glasgow firm consists of various types and applications of the “ Pick-quick ” coal-cutter. One of these is a small size specially designed for steep workings. The machine is fitted with three-phase electric motor, with oil immersed controller. The exhibit is mounted at an angle of 45 degs., and is fitted with the firm’s patent safety appliance for operating at high inclinations. Two turns of a tautened guide rope are taken round each of two wheels at the side of the machine, which are fitted with rack gear which comes in operation in the event of the haulage rope breaking. A medium size coal-cutter, with three-phase electric motor, is fitted with the usual facilities for slewing, tilting, and raising and lowering the cutter bar, and is with cutter bar 4 ft. 6 in. long, whilst a large size, similarly driven, is fitted with a cutter bar 7 ft. long as used for deep undercutting in seams which, as in some cases in Yorkshire, do not part well from the roof. Another type is the small size (15 in. over all in height) with direct current motor adjusted for overcutting. It may be noted that these machines have been worked in connection with a small fan for removing the debris and dust from the cut. It has been found that the induced current of air prevents the dust-laden atmosphere from rising, and so causing discomfort to the coal-cutter attendant. Another of the small size machines is shown equipped with compressed air motor. The motor- is of the two- cylinder single-acting high speed type, with crank shaft arranged in the long axis of the machine. These small size compressed air machines are cutting on inclinations up to 50 degs. Air-driven machines of medium and large sizes also shown are operated by motors of the four-cylinder high-speed type. The cylinders of these machines have removable liners, so that piston area suitable to the air pressure available can be provided. Messrs. Mavor and Coulson do not restrict themselves to the bar type of machine, and different sizes of the Samson disc machine are in evidence. The disc machines are not made for undercuts over 3 ft. 6 in., as