588 THE COLLIERY GUARDIAN. March 22, 1918. No. of furnaces, Inc. (+) or included in the dec. (-) returns, in blast in Feb. 1918 Districts. at end of on a f Feb. Jan. Feb. Month Year England &; Wales: 1918. 1918. 1917. ago. ago. Cleveland 75 .. 78 ... 75 ... - 3... — Cumberland & Lancs. 34 ... 31 ... 30 ... + 3 .. + 4 S. and S. W. Yorks ... 13 .. 13 ... 13 — — Derby & Nottingham... 34 .. 34 ... 28 — + 6 Leicester, Lincoln and Northampton 29 ... 30 ... 28 ... - 1... + 1 Staffs and Worcester... 28 ... 29 ... 30 ... -1... - 2 S. Wales & Monmouth 13 ... 13 ... 10 — + 3 Other districts 4 ... 4 ... 5 — - 1 1 ■ — — 230 ... 232 . 219 ... - 2... +11 Scotland 65 ... 62 ... 71 ... + 3... - 6 ■ - ■ ■ ■ -- Total, U.K 295 ... 294 ... 290 ... + 1.. + 5 Iron and Steel Works.—Employment at iron and steel works was very good, showing an improvement on a year ago. There was again a shortage of labour in all districts. According to returns relating to 118,887 workpeople, the number of shifts worked during the week ended February 23, 1918, was 682,976, showing an increase of 8,461 (or 1'3 per cent.) on a month ago, and of 43,350 (or 6'8 per cent.) on a year ago. Engineering.—These trades continued to be extremely busy during February and a great amount of overtime was worked. There was less pressure in munition factories, and some increase in the percentage unem- ployed of female workers, but there was a demand for skilled men in other engineering work. Trade unions with 314,430 members (mostly in skilled occupations) reported 0'1 per cent, unemployed at the end of Feb- ruary compared with 0’2 per cent, a month ago and 0T per cent, a year ago. Tinplate.—The number of tinplate mills working at the end of February showed an increase of 20 compared Fig. with the previous month. Difficulties in securing a supply of steel bars, and of delay in transit of raw material, were reported. The number of mills making steel and galvanised sheets working at the end of February showed an increase of six as compared with both a month ago and a year ago. Nuts, Bolts, Nails, &e.—Employment was good on the Tyne, and at Birmingham and Smethwick, and very good at Blackheath and Halesowen; at Darlaston it showed a decline. Employment was very good with shoe rivet and wire nail makers at Birmingham and Smethwick. Tubes. — Employment was good at Birmingham, Wednesbury and in South Wales. Wire.—Employment continued good. Disputes.—Four new disputes occurred in February and 4,857 persons were affected, directly or indirectly. At Mansfield 1,770 persons were idle for about 12 days through a dispute arising out of the striking of a pit boy by a corporal. The pit boys were prosecuted. At Barnsley 2,477 workers were idle for 10 days through a dispute arising out of coke oven workers’ demand for payment at the rate of time and half for week-end work and other concessions. An agreement was reached involving advance in wages to coke oven workers and fixing payment for week-end work at the rate of time and quarter on certain conditions. Wages.—In January-February wages in coal mining were increased by a net weekly sum of £600, affecting 15,000 workers. In iron mining the net advance, £2,200, affected 8,000 persons. In North Lincolnshire the iron- stone miners and quarry men (as from January 20) an increase, under sliding scale, of 20J per cent, (merging a bonus of 8d. per shift given from October 13 in lieu of 12J per cent, bonus), making wages 79J per cent, above the standard of 1909, plus war bonus of Is. Id. per shift. An increase or bonus was given to blastfumaeemen, gas-producer men and steel melters. Accidents.—The workpeople killed in February by accidents at mines of all kinds was 97 (83 underground and 14 surface), compared with 93 a year ago. Mr. C. E. Paterson has been appointed certifying surgeon under the Factory and Workshops Acts for Farn- borough (Hants.). Vacancies for certifying surgeons at Clwtybont (Carnarvon), Wilton and Birstal are notified. Trial Borings for Petroleum.—Lord Cowdray’s offer to spend, if required, £500,000 in boring for oil in this country has been taken up by the Government. Arrangements have been made for trial bores to be sunk by Lord Cowdray’s firm in a locality where petroleum geologists expect to find oil. Mr. Bonar Law stated in the House of Commons that a satisfactory agreement had been come to with a firm which is to undertake the work. THE MANUFACTURES OF MAYOR AND COULSON LIMITED, GLASGOW. As mentioned in our issue of December 21, 1917 (p. 1187), when we reported the visit of the West of Scotland Branch of the Association of Mining Electrical Engineers to the works of Messrs. Mavor and Coulson Limited, and on which occasion our representative was Fig. 1 present, we now propose to deal briefly with the chief manufactures of che firm. Dynamo and Motor Department. To the colliery engineer Messrs. Mavor and Coulson Limited are perhaps best known as makers of the bar coal cutter, but primarily they are manufacturers of electrical machinery. The first public supply of 2. electricity in Glasgow was from a generating station erected and equipped by this firm in 1885. In 1889 the Corporation of Glasgow purchased the electricity supply undertaking, and in the same year the manu- facture of electric motors and generators was started by the firm. In 1897 the expansion of the business Fig. n ■•'‘di '-■A8'-'-.'' . -5 . lit 4 J ' II: @ Ijl ‘ < necessitated a transfer of the works to the present premises in Broad-street. • Modern manufacturing tends to, and in fact can only reach perfection by, specialisation, and Mavor and Coulson have largely concentrated their attention on the manufacture of electrical machinery for mines and the equipment of power plants at collieries. The firm have, however, equipped many large factories, mills, etc., with electricity, and at the present time have a number of important power installations in hand. The patented tube-cooled totally enclosed motor manufactured by Mavor and Coulson is a speciality which should appeal more than it has done to the mining electrical engineer. Fig. 1 shows the con- struction of this motor. It is compact and of robust design. Air is circulated through the tubes by means of a fan, the improved cooling effect enabling a considerably increased output to be obtained from a motor of given size. The advantages over the ordinary totally-enclosed motor—namely, smaller weight and bulk—are of particular value for underground work. In the case of the standard d.c. motors these are con- structed so that the shell of the ventilated type can readily be converted into a flame-proof case if desired. Inter- poles are provided in all machines above a certain output to ensure sparkless commutation with fixed brush position. Fig. 2 shows one of the firm’s standard haulages. On the occasion of the visit a number of large gener- ators and motors for national factories, collieries, etc., were seen in course of construction. Switchgear Department. Messrs. Mavor and Coulson market an extensive range of mining switchgear, and a well-equipped depart- ment is devoted solely to the manufacture of these products. The firm’s long experience with practical mining conditions has enabled them to produce designs which are eminently suitable for the purpose. The range of gear comprises switchboards of any size and capacity, high tension truck and ironclad unit type switchboards, both flame-proof and for use in non-fiery mines, switch and fuse panels, starting panels, distribu- tion boxes, distribution pillars, controllers, resistances, starters, regulators, gate-end boxes, junction boxes, etc. A three-phase l.t. power switchboard built recently, com- prises 14 panels each controlling one three-phase feeder, whilst the bus bars carry 5,000 amperes per phase. This switchboard was supplied, along with others, to the order of a Government department, but is a good example of the type of gear supplied for colliery power and sub-stations. In ironclad switchgear Messrs. Mavor and Coulson have carried the principle of unit construction to an extent which enables them to build this type of switchboard to meet almost any requirements. They have at present under construction, to the order of a leading Scottish colliery company, a totally iron-enclosed switchboard for the control of the company’s power supply. The board is equipped with all the various switchgear pertaining to generator control, and com- prises overload and reverse current circuit breakers, ammeters, voltmeters, equalising switches, rheostats, etc., and apparatus for control of the various feeders. Fig. 3 shows an ironclad switchboard for colliery use. In the flame-proof switchboards each of the various units is fitted with a patent explosion relief valve of novel construction, as shown in fig. 4. Special notice is directed to the haulage-control pillars shown in fig. 5. This type of apparatus has been specially designed for use on electric haulages, and embodies the complete control equipment for a haulage motor. The pillar contains a barrel-type motor, grid resistance, renewable fuses, cut-off switch and ammeter-all these being con- nected up and thus making the pillar ready for the reception of the supply and motor cables, which are the only ones required. The consequent saving in cost of installation, together with the compact yet accessible construction, are the claims made for this haulage- control pillar. There is a constant demand for these pillars, nearly 20 having been recently supplied to one colliery company alone, which is clear proof of the soundness of the claims made for this apparatus. Mining Machinery Department. This department undertakes the supply of under- ground machinery, including coal-cutters, haulages, pumps, etc. For many years Mavor and Coulson’s name has been associated with that of the Pickquick bar coal-