1186 THE COLLIERY GUARDIAN. June 6, 1913. They]’have had an opportunity for community and discussion that does not often present itself, and, on this account alone, the Exhibition serves a useful purpose. We give in the following pages an illustrated descrip- tion of the various exhibits:— THE EXHIBITS. DAVIDSON AND CO. LIMITED. A full-size model of a “ Sirocco ” mine fan occupies one of the stands of Messrs. Davidson & Co. Limited (Belfast) and serves as an office. The size of fan it represents is a No. 44 of the double inlet type, having a wheel of 77 in. Such a fan would have the approximate capacity of 120,000 cubic feet of air per minute against 4 in. water-gauge, and would require about 100-horse power for its operation. "A 20 in. high-pressure fan is shown in operation on the stand delivering l;250 to 2,800 cubic feet of air per ! minute against 2 to 10 inches water-gauge. The wheel is of the usual patent “ Sirocco” construction, and ball either horizontally or vertically up to 20 ft. The “ Meco ” P.V. 15 air-feed stoping drill weighs 64 lb. and is for use in metal mining where extremely hard rocks, such as tin, cabal, quartz and other extremely hard materials require to be drilled. The “Meco” No. 18 hand-rotated hammer drill weighs 331b. and is in considerable use for sinking and stoping purposes in metalliferous mines and granite quarries ; it is adapted for very hard rocks in which ordinary hammer drills will not bore, and where previously heavy percussive machines were utilised; it will drill holes up to 20 ft. deep vertically. The “ Meco ” drill steel sharpening and forging machine is exhibited publicly for the first time, and the makers guarantee that a man will sharpen 50 ordinary drill bits in half an-hour as soon as he has become accustomed to the machine ; it is claimed to be the only one on the market which will satisfactorily forge a Z -bit. The machine is also designed for collar jumping on drill steels. This attachment means a very big saving in those mines where difficulty is encountered due to drill steel breakages. weighs 102 lb., and is usually known as the one-man machine: it is particularly adapted for difficult seams and awkward conditions. A “ Meco ” coal-cutter, 3 in. diameter cylinder, is shown complete, mounted on a quadrant with column, fitted with the firm’s latest type expansion valve gear, mitable for all moderate coal- cutting conditions, weighs 3021b. The “Meco” coal- cutter, 31 in. diameter cylinder, is a strong and powerful machine, suitable for use in all conditions where a powerful machine can be employsd ; its weight is 4141b. The “Meco” rock drill, 3^in. diameter cylinder, is a heavy type percussive rock drill mounted on tripod ; it weighs 556 lb. Turning finally to rescue apparatus, there are shown two complete “ Meco ” rescue apparatus of the latest design, fitted with helmet and a mouthpiece. These apparatus are also shown with the positive pres- sure fitting, which is on one of the firm’s most recent improvements. Refillable regenerators are shown, with which the cost of practice is now reduced to 9d. per man for two hours. Smoke helmets with different types of bellows are exhibited, and a smoke mask for use over “ Meco ” Drill-sharpening Machine. bearings are used to enable the fan to be driven at high speeds with the minimum of friction. The two bearings are supported on the side of the casing, and carried in a single sleeve bracket, thus ensuring absolute rigidity and perfect alignment. Grease lubrication has been adopted, so that the fan can run for months without any attention. A model fan which measures 171 in. in diameter and is of the double inlet type, demonstrates a method of reversing the direction of air current to meet the requirements of the new Mines Act. The fan is designed to act normally as an exhauster, but is fitted with swinging doors in the air drift and erase chimney, by means of which it can take its supply of air from the atmosphere and force it into the mine. A mine fan bearing shown on the stand is provided with an adjustable soleplate by means of which the alignment of the shaft can be readily adjusted in a very short time. The “ Sirocco ” hand-driven fan has been designed to supply temporary ventilation in confined spaces when mechanical power is not available. It can be fitted with volumetric or pressure nozzles, the former being most suitable where a volume of air is wanted at no great distance from the fan, the latter when the air blast is to be conveyed by a flexible hose screwed on to the nozzle. The fan on exhibition can deliver from 75 to 300 cubic feet of air per minute with free intake and discharge. A No. 8 “ Sirocco ” dust fan connected to a length of ducting is also shown in operation on the stand. The wheel is the distinctive feature of the “ Sirocco ” centrifugal fan. It consists of a number of narrow curved blades, and has a far larger volumetric capacity than the usual paddle-wheel type. The fan is built in 23 standard sizes, from 5 in. in diameter up to 100 in. The fans may be driven by belt or direct-coupled to engines or motors. There are six different methods of direct-coupling, depending upon the size of the fan and the duty it has to perform. MINING ENGINEERING COMPANY LIMITED. This firm have sent from their “ Meco ” Works (Moorfields, Sheffield) a number of their specialities, including conveyors, hammer drills, rock drills, coal- cutters, riveting and chipping hammers, rescue apparatus, &c. The “ Meco ” trough conveyor is a cheap efficient type of a compact and rigid form, the chief advantages of which are moderate first cost, low over-all height and quiet running; it can be arranged horizontally or at a slight upward inclination. The stroke of the special air engine can be varied to suit the conditions. The whole equipment is simple and reliable and requires practically no attention. The conveyor is shown with different types of drive from the air engine. The following hammer drills are shown:—The “ Meco ” hammer drill No. 2 is in extensive use in collieries in this country—more particularly on the coal face; it weighs only 27 lb. and is constructed throughout of steel, even to the rifle and guide nuts; it is particularly adapted for all those conditions where a light, rapid rotation machine is required. The “ Meco ” hammer drill No. 4 weighs 35 lb. and can be used in practically all stonework met with in a mine. It can be supplied suitable for either hollow or twist drills. The “Meco” hammer drill No. 6 weighs 401b. and is adapted for all severe work which may be encountered, and particu- larly for sinking purposes; it is suitable for drilling holes “Meco” Hammer Drill with Hand Rotation. Various sizes of the “Meco” riveting and chipping hammers to suit different conditions are shown. The “ Meco ” sand stampers are particularly designed for use in foundry work and in connection with ferro- concrete work. Experience has proved them to be great labour savers. A small size “Meco” pneumatic boiler scaler is another speciality shown. In coal-cutters we may mention the “ Meco ” light- weight type coal-cutter, 2| in. diameter cylinder, which ■ I ■ nl, “ Meco ’’ Rescue Apparatus. short distances. Dr. Bratt's artificial reviving apparatus is shown in use along with different types of reviving apparatus, and a hand oxygen pump for charging cylinders for rescue apparatus. CROSSLEY BROS. LIMITED. The exhibits of Messrs. Crossley Bros. Limited (Openshaw, Manchester), consist of a Crossley gas engine in motion of the electric lighting type, capable of developing 59 5 maximum B.H.P. at 200 revolutions per minute. The cylinder of the engine is supported for the whole of its length, securing freedom from movement and steadiness in working. The governing is effected by means of patent variable admission governing gear, which varies the strength of the charge in proportion to the load, an impulse being given on every working stroke, thus ensuring the- minimum variation in speed. The engine has balanced crank and splasher guard and is fitted with electric ignition.