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The Structural Engineer

UNDER the designation “Bauxite, or Aluminous Cement" may be grouped cements manufactured by burning in nearly equal proportions lime and bauxite until fusion, or almost until fusion, as the case may be. Such cements prepared by fusion are at present manufactured on a commercial scale by three firms : The Société Anonyme des Chaux et Cyinaents de Lafarge et du Teil, the originators of this new type of cement, who started experimenting as far back as 1897, took their patent in 1908, and reached the commercial stage in 1914, produce Ciment fondu (Registered Trade Mark) at le Teil (Ardèche) by use of a water-jacket, and Ciment Electro-Fondu (Registered Trade Mark) by use of the electric oven at Moutiers (Savoie). Yearly output about 50,000 tons. Mons. T.J. Guéritte

The Structural Engineer

MEMBERSHIP THE present membership of the Institution of Structural Engineers, and its comparison with the figures for the two previous years, is shown in the following table:-

The Structural Engineer

It is claimed for the Standard Concrete Machine that it is designed to give unrestricted scope in the manufacture of concrete products. An idea of the range covered by this machine, some of the products of which we illustrate, may be gathered from the fact that the largest casting which can be produced has a length of 6 ft. and a width of 3 ft., and any thickness within the limit of the maximum weight of the product, which is two tons. Also a number of products can be made at one operation of the machine; for example, three or four lintols, four or more cills, two, three or four kerbs, and six or more channels. The product can be moulded on any or all of its four sides; and it can be made solid or hollow, ornamented or plain.

The Structural Engineer

Solution to Problem Sir,-Mr. T. J. Evans' question (on p. 171) is very suggestive of one set by an examiner too indolent to realise all the trouble he is going to give the candidate.

The Structural Engineer

THE PRESIDENT, in tendering the thanks of the members of the Institution to Dr. Salmon, said that he must have had very great courage indeed to have read a paper such as the one he had read. There was a great deal of good food for thought in it, amid a great deal that wouid make people think, which was what the Institution, and all other similar institutions, were out to do. With regard to altering the standard notation, this could not be altered, and he wanted the members to stick to it. (Laughter.) If they did not understand Dr. Salmon’s notation, then let them get a book and look it up. The greater part of the members would understand Dr. Salmon’s notation as well as they understood the standard notation. He had been very interested in the last slide, showing the work done in Germany, and it was up to us to do the same thing. He was looking forward to the time when the Government, having spent enough on the various schemes they had on hand, would advance some money for research on the lines indicated. The research could not be done privately. The manufacturers were already spending a vast amount of money in this country, and until the Government came to our aid we should never be able to do what the Germans and others were doing.

The Structural Engineer

A meeting of the Institution was held at Denison House, Vauxhall Bridge Road, London, S.W., on Thursday, March 20, 1924, the President, Major James Petrie, O.B.E., M.I.Struct.E., in the chair, when a paper on “The Inspection and Testing of Structural Materials” was read by Mr. H. J. Davey, M.B.E., M.I.Struct.E.

The Structural Engineer

Foreign Competition. An article which appeared in a recent issue of the "Morning Post" contained some striking figures, presented in the form of a chart, comparing current wages in various industries, after making allowance for the increased cost of living, with those received by the workers in 1914. The object of the article in question was to demonstrate the necessity of securing for national industry a policy which should "level up" wages "by a reasonable measure of shelter against indiscriminate world competition." With this end in view it was shown that the real value of wages had increased during the past ten years in those branches of industry which are immune from overseas competition, or have been protected by a tariff, while in trade which compete with similar trades in foreign countries the real income of the workpeople has diminished. Apart altogether of the success or otherwise of this demonstration in favour of artificial protection by tariffs, the figures given by the "Morning Post" certainly showed that wages are comparatively high in industries which are naturally sheltered by the fact that the goods produced or the services rendered are disposed of internally, while in those industries which are engaged largely in manufacturing for export, or are otherwise particulsrly subject to foreign Competition, the real income of the worker is decidedly lower than before the war. Examples of the former class are railway men, bus-drivers and bakers, whose real wages are shown to have increased by 30 per cent., 12 per cent. and 18 per cent. respectively, while among workers in the "unsheltered" industries, shipwrights receive 30 per cent. less than their pre-war wage, tinplate and steel, workers 20 per cent. less, and cotton workers 7 per cent. less. These figures show the economic advantages of the workers in the naturally sheltered industries, and an examination of the dividends paid by industrial companies shows that the capitalist in some of the sheltered industries is in an equally good position. Three companies owning large West End stores, which may be taken as an example of undertakings whose business is entirely free from foreign competition, paid an average dividend on their ordinary shares of 22 per cent. for the last completed year, compared with 19 2/3 per cent. in the last pre-war year. On the other hand, four large iron, shipbuilding and engineering companies, taken at random as representatives of the unsheltered industries, paid an average of 12 2/3 per cent. on their ordinary capital before the war, and only 4 2/3 for the past year. The case of this latter group is, perhaps, exceptional, as the engineering and kindred industries have suffered more than many others from the necessity of adjusting their works from war to peace activity; but other trades, such as shipping and some branches of the textile industry, into which foreign competition enters, have also been seriously affected. These facts are now recorded, not as an

The Structural Engineer

THERE can be little doubt that the building material of all others that will enter into the reconstruction of our country is cement. This being undoubtedly true, it is of exceptioml interest to record that, availing themselves of the opportunity afforded by the Building Exhibition at Olympia, The lnstitution of Structural Engineers convened a Coagress of delegates from all parts of the world to read papers on and to discuss in all its aspects, the manufacture, chemical properties, possible refinement and improvements and constructive possibilities of cement. A conference duly met on April 22 and the delegates were received at the Building Exhibition, Olympia, by MAJOR JAMES PETRIE, President of the Institution of Structural Engineers, and were conducted round the exhibition. They were afterwards entertained at lunch by the Council of the Institution of Structural Engineers and the directors of the Building Exhibition. MAJOR PETRIE, who took the chair, in proposing the health of the delegates, said they included some very distinguished men from all parts of the world. He welcomed them warmly, and felt sure that they would find, in the many papers which had been contributed, material which was both interesting and instructive as illustrating the difficulties which confronted structural engineers in their ordinary everyday work.

The Structural Engineer

Then as to mediums, the best results, certainly when covering large surfaces, are obtained with water or oil. Spirits are already volatile, and if super-aerated are apt to give trouble by too rapid or "spotty" drying. This is not so immediately felt when dealing with decorative or small work, but presents considerable drawbacks in rough work.

The Structural Engineer

AS we have previously announced the Government of New South Wales has accepted the tender of Messrs. Dorman, Long & Co., Ltd., of Middlesbrough for the construction of the North Shore Bridge over Sydney Harbour. We have now the pleasure to present the accompanying illustration showing the bridge ,as it will appear when completed.

The Structural Engineer

THE Committee of the Institution of Civil Engineers appointed to investigate the deterioration of structures exposed to the action of sea water reported inter alia in 1920, that "it is taken by most engineers as definitely determined that properly constituted Portland cement concrete, employed as it should be, may be relied upon to produce sound and permanent work." F.E. Wentworth-Sheilds

The Structural Engineer

To the user of Portland cement the question of irregularity of setting time is so important and the reasons thereof still so far from assured settlement, that the author makes no apology for the presentation of some notes on the subject at this International Conference in the hope that discussion will throw further light on this important problem to the structuralengineer. In the course of the author's somewhat lengthy experience in the cement industry he has found that the factor in the use of cement least understood, and productive of the most difficulty, and sometimes disappointment to the structural engineer and general user, is the property which cement possesses- in combination with water-of consolidating itself into a permanent rock-like mass, enlocking in the process any materials with which it is in contact and which are not chemically repellent. H.K.G. Bamber

The Structural Engineer

The Section Modulus and Moment of Resistance IN an ordinary beam of homogeneous material we obtain the section modulus in tension or compression by dividing the moment of inertia by the distance from the neutral axis to the tension or compression edge of the material.

The Structural Engineer

ALTHOUGH the angle is the section most commonly used as a strut, we have had some doubt in the past as to the actual strength of steel angle struts when connected in the manner commonly employed in roof-truss, trestle and other framework. In Bulletin No. 218, issued by the United States Bureau of Standards, results are given of an investigation into the subject made by Messrs. A. H. Stang and L. R. Strickenberg.

The Structural Engineer

ALTHOUGH this Conference is to deal chiefly with the properties and uses of cements we think that engineers and users of cement generally will be interested to receive some account of methods investigated by British Portland Cement Manufacturers, with the object of reducing the cost of manufacture, and so-of the utmost importance to the user-of reducing the cost of the finished cement. J.W. Christelow

The Structural Engineer

THE intention to apply to the ruins of Tintern Abbey only such repairs as would not affect the beauty or the antiquarian interest of the building very seriously complicated the difficulty of its preservation by the Historic Buildings Branch of H.M. Ofice of Works. William Harvey