438 _________________________________________________________________________________________________________________ THE COLLIERY GUARDIAN. February 28, 1913. approximately 1 gramme, shot into each, from a little scoop or spoon of suitable size. They could then all be weighed and afterwards put in a large airtight vessel —say a desiccator vessel—which is filled with CO2. When a determination is to be made a bottle can be taken out and the whole of its contents, as far as may be, tipped into the weighed vessel to be used for drying or other determination and the bottle reweighed. By this means, a weight slightly less than that originally in the bottle is taken and the error of assuming that the weight—probably a few milligrammes—left behind represents the coal in its original state is inappreciable. So that, however long a period after the bottling-off may elapse before a small sample is used, any change in weight such as is noticed by Mr. Stansfield is negligible, so long as it is not so great as obviously to affect the whole character of the coal. An example will make this clear:— Grammes. (b) Weight of bottle and coal at time of filling... 13 5061 (a) „ of bottle................................ 12 4321 Coal in original state ....... 1’0740 (c) Weight of bottle + coal after, say, 3 weeks... 13’5032 Alteration ................. 0’0029 (c) Is taken for information only. (d) Weight of watch-glasses to be used for drying 11’6317 ....... (b) As above..................................) 13’5C61 (e) Weight of bottle from which coal has been > tipped out ............................. ) 12’4379 Weight of coal taken for moisture determina- tion ....................................................... 1’0682 Weight to be taken as total weight before drying ...................................... 12’6999 (/) Weight after one hour drying .............. 12’5687 Loss (= water) ............. 0’1312 The proportion of total alteration, 0’0029, is inappre- ciable on the 0’0058 gramme left in the bottle, and therefore a (virtual) correct weight of original coal can be obtained by this means. Another plan which we think, on the whole, will probably be found, when sufficient work has been done, to be most convenient in all cases for the determination of water in a bulk is to weigh 50 or 100 grammes and to determine the water by the xylene method mentioned by Dr. Constam. We do not advise that ground samples of coal should be emptied from the containing vessel and spread out for mixing unless a portion is set apart each time to form a determination of water before mixing the sample. It is safer to place the sample in a cool place for some time and then to stir it with a spatula before taking out a portion for a determination of water. (To be continued.) ________________________ AUTOMATIC WATERING DEVICE FOR MINE GALLERIES.* Within the last few months a device has been tested at the No. D/VI. shaft of the Consolidation Colliery for watering mine galleries automatically at certain intervals in order to prevent the propagation of coaldust explosions. The perforated pipe a (figs. 1 and 2) is connected with the hydraulic main b by a U-tube c. The opening and closing of the tap d, and consequently the discharge of the water from a, are effected by operating the lever e, the movement of which is restricted by the stops/and o b. Fig. 1.—At Rest. Fig. 2.—In Operation. g. A weight la is mounted on one end of the lever, and a water tank i on the other end. When the device is in the position of repose (fig. 1), a pipe &, branching from the main 5, delivers water into the tank i at a rate controlled by the setting of the tap I. The discharge tap m of the tank remains closed so long as the lever n rests on the stop o. The one arm of the lever e is provided with a track p for a travelling ball q, in order to provide gradual compensation for the loss in weight during the escape of water from the tank i. When the tank is filled to such a height that the moment of rotation of the weight h is overcome, then the lever e moves over into the position shown in fig. 2, so that the * Gluckauf. tap d is opened and water is admitted through the bent pipe c into the perforated sprinkler a. At the same time, as soon as the lever passes beyond its middle position, the ball q rolls along to the further end of its track. By striking against the nose r the lever n opens the discharge tap m of the tank i, thus allowing the water to escape. Since the travelling ball now exerts a greater leverage than when the device is in the position of repose, a correspondingly increased volume of water can issue from the tank, and therefore also from the sprinkling pipe, before the weight h returns the lever to its initial position. The time the device operates can be accurately adjusted by altering the setting of the supply tap I and the throttle valve s. The cost of the device is about £4 5s., including mounting and connecting to the water main ; and it has proved reliable in action. ____________________________ HEW MINING PLANT AT SCOTTISH COLLIERIES. [By oub Correspondent.] At present, the colliery engineering firms in Scotland are very active carrying out orders for new installations or renewing machinery and appliances. Export orders, too, are well in evidence, and particularly is it to be noted that firms specialising in electric work have well-filled order books. Reference has been made in certain quarters to the backward state of Scottish collieries in regard to introducing up-to-date plant, but many leading firms are now modernising their principal collieries and the utmost advantage is being taken of the most approved labour-saving apparatus. The Kirkcaldy firm of engineers, Messrs. Douglas and Grant Limited, Dunnikier Foundry, who specialise in winding and pumping machinery, have at present a good deal of work in hand supplying electric winders and haulages for different parts of the country and abroad. They are also completing a very important pumping installation a^ the large new Wellesley Colliery, near Methil. Another firm who do much colliery work in the way of manufacturing every description of wire rope—Messrs- Allan Whyte and Co., of the Clyde Patent Wire Rope Works—have been occupied with orders for both home and foreign markets. That large firm of engineers and electricians, Messrs. Mavor and Coulson, Glasgow, are specialists in electrical equipment. They have a large export trade in coal-cutting machinery, and are selling the Pick-quick bar coal-cutter and the Samson disc coal-cutter. For the “ Ceag ” electric lamp, Messrs. Archibald Baird and Son Limited, Hamilton the proprietors of the Clyde Steel and Engineering Works., are the local agents. The “ Stach ” lamp is being exhibited by Mr. Sidney Simon, Glasgow. Messrs. Mather and Platt, whose works are at Manchester, have a wide Scottish connection with a head Scottish office in Glasgow. One of the best of their recent complete contracts was that at an English colliery. Within the last two years the whole of their A.C. and D.C. machines have been entirely remodelled, the firm having given attention to the best types in use at Continental collieries. At this English colliery the generating station contains three Mather and Platt alternators, each of 300 kw. capacity, wound for 2,600 volts, 50 cycles, of the revolving field type, coupled direct to Beiliss and Morcom’s engines. The excitation of the alternators is provided by a motor generator from the high-tension side, the stand-by supply from a direct-coupled D.C. set being also available. The arrangement for the supply of condensing water has had considerable thought on account of the scarcity of water. The condenser discharge from both the electric power sets and the existing air compressors is carried to a hot well, and from this is lifted, by means of two Mather and Platt turbine pumps, to the cooling pond. These pumps each have a capacity of 2,000 gallons per minute against 70 ft- head when running at 1,450 revolutions per minute. The water passes from the pumps through spray distributing nozzles, whereby it is effectively cooled before recirculating through the condensers and compressors. Each of these two pumps is sufficient to deal with the whole of the condensing water required; they are driven by direct- coupled three-phase motors of 64 b.h.p. wound for 2,600 volts. An interesting pump installation is that of a vertical sinking pump driven by a three-phase motor, which recently completed the unwatering of a mine 500 ft. deep, after pumping continuously for over three years at the rate of 500 gallons per minute. Quite recently Mather and Platt supplied a gas engine of 450 b.h.p. for working off producer gas obtained from colliery refuse. Messrs. Alley and MaoLellan Limited, Glasgow, have supplied many of their Sentinel air compressors to collieries. The British Thomson-Houston Company are supplying a new colliery in Stirlingshire with electric winding equipment. This firm supplied the motor generator at the comprehensive installation ordered by the United Collieries Limited, Glasgow, for the Bredisholm, Calderbank, Ellesmere, and Clydeside collieries. Messrs. D. Selby Bigge and Co., engineers, Glasgow, were responsible for the electrification of these collieries, the transformers being supplied by the British Westinghouse Electrical Manufac- turing Company Limited. At these pits electrical energy is used for hauling and pumping, ventilating and coal- cutting. A feature of this contract is the linking up of the pits by bare aluminium overhead transmission lines. The system is so designed that either generating station may supply the complete network, or the stations may run in parallel. In regard to pit sinking, the British Hydraulic Engineer- ing Company, Whiteinch, Glasgow, supplied special cylinders to contracts at home and abroad. At present their plant is at work sinking two new pits near Bo’ness Dock for working coal under the sea. While the Scottish chain firms are well employed, yet trade is so brisk at present that the Brierley Hill firm, Messrs. Noah Bloomer and Sons, are executing work for the west of Scotland. These chains are for surface haulage, and an endless chain, approximately 1 mile in length, the whole hand wrought, and weighing 12 tons, is now in use in a Glasgow owned colliery hauling tubs of coal up an incline 4 mile in length, leading from the pithead to the railway siding. ___________________________ MINING AND OTHER NOTES. The employees of the Pinxton Colliery Company have decided to petition the Derbyshire County Council with a view to making tenable at the Nottingham University College mining scholarships obtained by students in Derby- shire. A useful booklet, containing tide tables and other general information as to the company’s collieries and shipping wharves at Neath, has been issued by the Main Colliery Company Limited. This company enjoys a position unique, we believe, in South Wales, in possessing their own railways, wharves and collieries, thus greatly mitigating the consequences of traffic congestion, from which many of their neighbours at times suffer acutely. The wharves have a water frontage of 1,500 ft., with ample storage sidings, and eight tips, three of which can be put to work simultaneously on the same vessel. The products of the collieries include through-and-through steam coal and Hughes’ seam coal (a house coal sold in cobbles, large and small nuts, small, and duff). Two lectures will be delivered at the Royal Society of Arts by Mr. Francis William Goodenough, on “Coal Gas as a Fuel for Domestic Purposes,” on Mondays, March 3 and 10, at 8 p.m. At a meeting of the Society of Engineers, on Monday, March 3, 1913, at the Institution of Electrical Engineers, Victoria-embankment, W.C., Mr. Arthur Valon, the presi- dent for 1913, will deliver his presidential address. Messrs. Yeadon, Son and Co., Leeds, have received an important order from the Great Indian Peninsula Railway Company, to supply them with a complete briquette plant to be erected at their Mohpani Colliery, India, for con- verting their small coal into briquettes suitable for consumption on their own locomotives. The above company had previously sent some of their coal to Messrs. Yeadon to be tested in one of their briquette plants working in this country. Great satisfaction is felt in the Doncaster district, says our local correspondent, that the Corporation is at length yielding to the pressure brought upon it by public opinion by the Archbishop of York, the Local Government Board, the Royal Sanitary Institute, and in other influential quarters, to tackle the great problems with which it is con- fronted as a result of the development of the new South Yorkshire coalfield. It will be easily remembered that the problems of borough extension and town planning have been before the Council for the past three or four years, with little result till lately, when, as a consequence of an almost irresistible wave of public opinion, the town planning of the district is being seriously taken in hand. Now comes welcome news in regard to borough extension. Last week-end the Corporation held an important meeting in committee, and as a result of this it was decided to at once proceed with the extension of the borough. The scheme which the Council propose to adopt provides for the incor- poration of Balby, Wheatley, Carr House and Elmfield, and Hexthorpe, all of which places are outside the borough, but so contiguous to it as to be practically part and parcel of it. The Corporation have lately embarked upon a big sewerage scheme embracing this area, so that the provision of this