February 6, 1914 THE COLLIERY GUARDIAN. 297 It is notable also that the externally-fired cylindrical multi tubular boiler the standard low-pressure boiler of the United States, has never obtained any substantial footing in this country. The proportions of this class of boiler do not exceed 1’5 per cent., and they are included with other types under heading (7i). In the case of vertical boilers, heading (c), there is no doubt that an increasing number have come under the inspection of the insurance companies in recent years owing to the operation of legislation, and the figures are rather an indication of this fact than of a general increase in the use of this type. Lancashire Boilers.—Up to a few years ago this boiler was considered the standard boiler for all large power installations, but now in the larger electric power stations water-tube boilers are more generally adopted. The Lancashire boiler reached its present form of design some years ago, and modern improvements have been only in the direction of details of construction. Up to pressures of 160 lb. it is a very satisfactory boiler for factories with ordinary classes of feed water. As pressures increase above this difficulties of design and construction arise. Movements towards high pressures therefore tend to favour the water-tube boiler. Although in the number of this type the figures show a relative decrease, it is probable that the total power of this type of boiler has increased over the period covered ; thus there has been a gradual increase in the size generally adopted for new boilers somewhat as indicated below :— Sizes of Lancashire Boilers. 1880-1890. Ft. in. 1890-1900. Ft. in. 1900-1910. Ft. in. Diameter about.. ..7 0 .. 8 0 9 0 Furnaces ..2 9 3 2 3 7 Grate .. 33 sq.ft. .. .. 37 sq.ft. ... 43 sq. ft. It will be seen from the foregoing figures that this type shows a large relative increase in power per boiler (as measured by grate surface) for the new boilers put down. It is to be observed, however, that in water-tube boilers very much greater increase in power has taken place, thus:—In 1890 the power of an ordinary new water-tube boiler would be about equal to one Lancashire boiler, with an evaporation of 5,000 or 6,000 pounds of water per hour ; whereas at the present time, in various power stations, new water-tube boilers are put down equal to an evaporation of four or five Lancashire boilers evaporating, say, 25,000 to 30,000 pounds of water per hour. Cornish Boiler.—This shows a substantially decreasing proportion. Where larger powers are required, generally a number of Lancashire boilers are put down rather than single-flued or Cornish boilers, and the Cornish boiler is generally used only for such industries where it is desired to have an internally fired boiler of less power than a Lancashire boiler. Vertical Boilers.—This heading includes the ordinary vertical boiler with cross tubes in the furnace, also vertical multitubular boilers of various forms such as the Cochran boiler and the like. The increase shown by the figures for this particular type is, in some respects, unexpected, for it is well known that in small industries in the larger towns in which small vertical boilers previously were largely used for driving small engines and generally for small power purposes, the places of these small vertical boilers have been largely taken by gas engines and by electric motors with electricity from the town’s supply. On the other hand, steam is being used more generally for all kinds of heating purposes, and in many small industries vertical boilers have been installed for this purpose. In addition, the Quarries and Mines Act has brought a larger number of these boilers under inspection. Locomotive Type.—The figures show a steady increase. They do not cover locomotives on the main lines of the railways, but include works, shunting locomotives, traction engines, road rollers, steam motor wagons, portable locomotives on farms, and fixed locomotive type boilers. The locomotive type boiler is one of the most remarkable of the types in use. Probably, if it were to-day presented for the first time, nearly all engineers of experience would predict that owing to its complexity and rigidity it could not possibly work satisfactorily. It has, however, given satisfaction in various branches of industry, and has become practically the standard type of movable boiler on land. At first designed for railways, it continues practically in the same general form as was settled upon many years ago. The general qualities of this boiler are that it is a fairly economical boiler and is light for its power. Rastrick Boilers.—This is the ironworks boiler which obtained a certain vogue in some districts some years ago for the purpose of utilising the waste heat of gases from puddling furnaces and the like. It proved to be specially adaptable for purposes of this character, but is subject to abnormal risks in working. The one advantage of this type of boiler was its convenience as a working machine ; on the other hand, it was full of dis- advantages from the point of view of safety, and to-day new boilers of this type are seldom put down. Tor the purpose of utilising gases from re-heating furnaces and the like, water-tube boilers have been largely adopted, also vertical multitubular boilers, such as those made by Cochran, Davey’s and others. Also two-flued and three-flued horizontal boilers have been used for this purpose, and all of these are preferable to the Rastrick type. Plain Cylindrical Boilers.—This type is a rapidly decreasing one. It was one of the earliest as it is one of the simplest forms of steam boiler. Generally, its disadvantage is that it is short of heating surface, and the external shell being heated, is liable to various kinds of defects arising from differences of expansion, con- traction and the like. To overcome the deficiency of heating surface in the old days, increased length was adopted, and with boilers 5 ft. 6 in. diameter, lengths of 50 ft. to 70 ft. were reached. This great length led to defects and explosions owing to rip at the ring seam. Owing largely to the general realisation of the insecurity of this type in the long form it has become obsolete, and very few new boilers of this description are now being made. Water Tube Boilers.—These figures show an increasing proportion in point of numbers. If the figures referred to growth of power, the increase shown would be con- siderably more. The water tube boiler on its introduction here about 30 years ago was regarded as an undesirable class. The Babcock and Wilcox type, however, after introduction into this country, was much improved in detail and proved to have very advantageous qualities in many respects, and other successful types, such as the Stirling boiler, the Woodeson, and other varieties, have since been produced commercially. The water tube type has 200 150 100 50 150 250 200 100 30 1600 *0 20 30 40 50 60 70 80 90 1900 tQ PRESSURE LBS a: 250 -------r Y£AF?S. Fig, 5.—Diagram showing the Maximum Steam Pressures genoraHy adopted in New Boilers in the United Kingdom shown in recent years more life and movement in the production of variety and type than other boilers which are generally adopted for the production of power on land. An important feature of this type is the facility of design for high pressures. In the early days there was considerable competition between the Lancashire type of boiler and the water tube type, both as regards the power development in large electric stations, and also in textile and similar factories. The result of this struggle for position is that in the large electric power stations the use of the water tube boiler is general, and in the textile and similar factories the Lancashire boiler has retained its position. Water tube boilers have also been largely applied to utilisation of the heat of gases from re-heating furnaces and the like. One special feature of this boiler is that a good feed water is required. Increase in Pressures.—Pressures have increased as the result of the search for economy. Fig. 5 shows the gradual increase in the maximum pressures for which land boilers have been constructed at the periods indicated. The lower line indicates approximately the steam pressures generally adopted from this period onward in the case of Lancashire boilers for textile factories and the like. From about 1880, is to be dated the practical introduction of the modern water tube boiler, and the upper line may be taken as broadly indicating the trend of the maximum pressures in the case of water tube boilers, as adopted for electric power stations. With higher priced coal, a higher pressure of steam might be economically advisable, but, with a higher pressure, maintenance charges increase, and the working considerations on the whole, therefore, tend to regulate the increase of pressure to such a figure as is found to give broadly economical results. (To be continued.} Mr. John Knowles, of Brynn Mount, Westwood, Lower Ince, Wigan, Lancs, mining engineer, general manager of Messi s. Pearson and Knowles* collieries at Ince and Coppull, managing director of the Moss Hall Coal Company Limited, who died April 30 last, aged 57 years, left estate of the gross value of ^£4,617, with net personalty nil. SOUTH WILES INSTITUTE OF ETOiHEERS- Presidential Address. The ordinary general meeting of the South Wales Institute of Engineers took place at Cardiff on Thursday, January 29, when Mr. Henry T. Wales, the new president, occupied the chair. The following were elected to the institute :—George Cyril Blake, Llanelly; Archibald Corbin, Llanelly; F. H. Downie,Treforest; F. W. Gilbertson, Pontardawe; John Glasbrook, Sketty-court, Sketty ; Philip Jenkins, Abertridwr ; Archibald E. Jones, Clydach Vale ; Harry LI. Jones, Blaenavon; John Roberts, Wigan; and B. Williams, Lower Cwmtwrch, Swansea Valley. Mr. C. D. James, Seven Sisters, near Neath, was elected an associate member. A number of students at University College, Cardiff, and the new School of Mines, Treforest, were approved as student-members of the institute. The following office-bearers were elected for the session to fill vacancies :—Vice-presidents: Mr. Hugh Bramwell, Brynteg, Lian trisant; and Mr. Edward Dawson, Cardiff. Members of council: Mr. Theodore Vachell, Newport ; Mr. Thos. Arnold, Llanelly; Mr. W.‘ W. Hood, Cardiff; Mr. Leonard W. Llewelyn, Clydach Vale; Mr. H. Spence Thomas, Llandaff; Mr. A. O. Schenk, Swansea; Mr. J. W. Hutchinson, Tondu; and Mr. Clarence A. Seyler, Swansea. Presidential Address, Mr. H. T. Wales then delivered his inaugural address. He said that the membership of the institute had grown from 355 in 1901 to 710 at the present time. The total output of coal in South Wales was over 50 million tons in 1912, whilst the year 1913 would show a large increase on this figure, and there were now in progress several sinkings which would, within the next two or three years, add largely to these figures. Fortunately, the demand for coal all over the world continued to grow, and they might reasonably look forward to getting a fair share in the future of the market, provided that they were able to produce at a figure which would make it worth the while of the consumer to send orders to the district. Germany was competing with this country in coal output, and there was every prospect that this competi- tion would become keener by reason of the fact that the German Government encouraged any development of the natural resources of the country, whilst the large and steady growth of population provided ample labour for carrying on the industry. Dealing with oil as a source of power, the president said that as a large proportion of the output of coal in South Wales was used for supplying bunker coal to steamers, it was evident that this was the coalfield which would feel in the greatest degree any competition which might arise from the use of oil. The fact that the occurrence of oil was irregular and the life of oil wells comparatively short, made it difficult to see, how- ever, how oil could be looked upon as a permanent com- petitor with coal. It had also been calculated that the price of oil would not have to exceed 42s. per ton in order that it might compete commercially with coal at 18s. per ton. In the British Navy many vessels had been fitted to burn oil and coal together, and a few, of smaller size, had been constructed to burn oil only, but it was not likely that the large vessels would be constructed to burn oil only, unless the uncertainty of the oil supply had been provided for in some satisfactory manner. In his opinion there was no probability that oil would be used for propelling ships to such an extent as would interfere prejudicially with the dem&nd for steam coal, or its value. In the United Kingdom the coalfield which was most likely to be found in competition with South Wales was that lying in South Yorkshire. A recent visit to some of the newer collieries there left upon his mind a strong impression that witbin the next five years the coal from these new collieries would be often met in many foreign markets in competition with Welsh coal. The quality of the coal was not equal to the Welsh coal for steam raising purposes, but possessing an advantage of some shillings per ton in the cost of production, the coal would no doubt have to reckoned with as a competitor. Referring to the cost of production in South Wales, Mr. Wales said that, following upon the heavy increases, corresponding increases had taken place in the selling value of the coal produced, but it seemed to him very doubtful whether the selling prices now prevailing had not been forced up to a point which was distinctly detrimental to the trade development of the whole world. In addition to the increased rate of wages, much of the extra cost was the result of legislation. While some of the regulations were well designed for securing safety, others seem to betray a want of know- ledge or lack of consideration for the circumstances which arose in the daily carrying on of colliery opera- tions, and, altogether, there was a tendency to restrict the management to a defined groove to prevent the exercise of that initiative which was so valuable, not only in the direction of efficiency, but also in obtaining safety in working. It was quite possible to drill a soldier to such an extent that he became only a machine, and he feared that this might be the effect on colliery officials, whose minds were distracted from more important matters while endeavouring to carry out the detailed work which the new regulations required. In the course of further remarks, Mr. Wales said that the application of stonedust to the roads in collieries was not difficult or unduly expensive, and its adoption was worthy of consideration at all collieries where coaldust was a source of danger. About two-