October 16, 1914>. THE COLIIERY GUARDIAN. 819 Fan Testing, With Special Reference to the Measurement of Pressure. The meeting thereafter proceeded to discuss the paper by Mr. Thomas Bryson on “ Fan Testing, with Special Reference to the Measurement of Pressure.” Mr. William Davidson, in the course of a written communication, gave it as his opinion that Mr. Bryson’s paper was worthy of most serious considera- tion for several reasons. As the author had pointed out, when dealing with measurements of such small dimensions, even a small fraction of an inch gave erroneous results. It would surely serve a good pur- pose if this matter were seriously taken up, and an attempt made to arrive at the proper form of gauge to be adopted. If the correct water gauge be not arrived at in the first instance, it was hardly likely that the results obtained when the larger fan was set in motion would be satisfactory. Taking into consideration the important part ventilation played in mining, it was most desirable that the best results possible be obtained from the ventilator. More especially was this point empha- sised when they took into consideration the fact that in the future more air would require to travel, with con- sequent greater velocities. Mr. Bryson had supported his argument ably with a striking and most interesting equation. Indeed, he thought the author had put the point very neatly when he said that to get a proper water gauge reading the end of the tube must be taken out of the velocity and connected to the air current only by a “ capillary connection.” Mr. James Black said that this subject had formed the basis of several papers which had appeared in the Transactions. Nevertheless, the fact remained that at the present moment the measurement of the water gauge produce^ at the fan rested on a most unsatisfac- tory basis. Indeed, as things stood, it was almost impossible to make a fair comparison of the abilities of different fans. In the introduction to his paper the author made the following remarks :—” It is certain that the height of water gauge registered will be affected by the position and form of the gauge and on the velo- Fig. 1.—Diagrammatic Sketch of Testing Machine used in conducting Tests. a BMdlMiiMi»wniimiwifliBni!ll M w N HhiiiiOniiiiiimwBininiHimii bbhm GOD ODD Type A. Type B. 00 Type C. 00 Type D. an an Type E. Type F. AB 00 Type G. Type H. Fig. 2.—Types of Links used in Tests. city of. the air in the region of the gauge. Then, there is always the error of reading, which can never be eliminated.” He agreed with Mr. Bryson that the error of reading was one which they had to contend with. He did not know how the author reconciled that statement with the fact that in the tables accompanying the paper he gave the readings of the water gauge to yJ)oth of an inch. Personally, he considered if a water gauge could be read to TJoth an inch> there was little ground for complaint. In any fan tests he had attempted, he had never been able to obtain any such degree of accuracy. Indeed, he always considered him- self extremely fortunate to get a reading of 0’05 in., and, as a matter of fact, he found it required a prac- tised observer to take a reading of the water gauge to 0-05 in. Mr. Black thereafter proceeded at consider- able length to criticise some of the conclusions which Mr. Bryson had put forward in his paper, and, in this connection, he maintained that the author would require to make a great many more observations before he could consider himself justified in making the con-, elusions he had done. Further discussion was adjourned till next meeting. Tests on False (or Split) Links for Cut Chain Braes. Mr. John T. Wight read a paper on “ Tests on False (or Split) Links for Cut Chain Braes,” of which the following is an abstract:— The figures set forth in the following short paper record the results of a series of tests carried out at the Heriot- Watt College, Edinburgh. The primary object of these tests was the determination of the breaking strengths of the various types of false links at present in use, in order to settle which type of link is strongest, safest, and best for general use. The question is a very wide one, and it cannot be claimed that the results obtained, instructive as they are in regard to breaking strengths, can settle definitely more than a very few of the points raised in the investigation. The question of strength, important as it is, is in a large measure subservient to that of utility and safety in working, points which can only be settled by men possessed of a wide experience of colliery practice. With these latter aspects of the question the members are doubtless all familiar, but with respect to breaking strengths it is not likely that many opportunities have occurred of making comparative tests. It might be well at the outset to give a brief explanation of the construction and working of the testing machine, as used in these tests. Fig. 1 shows diagrammatically the arrangement of the machine, from which it will be seen that it consists of two distinct parts, namely, a loading end and a weighing end, both of which are attached to a common bedplate. The loading end consists of a hydraulic cylinder A, in which works a ram B. This ram carries a crosshead C, which is connected to the crossbeam E by means of four screwed rods D, working in nuts fixed in E. By rotating the gear wheels shown on the crosshead C, the four screwed rods can be rotated simultaneously, and the crossbeam E moved to any desired position on the bedplate, depending on the length of the test piece. To the crossbeam is attached a shackle F, so designed as to carry the various grips and dies. Water can be pumped into the hydraulic cylinder by means of a hand pump, and it should be noted that the effect of this is to move the shackle F towards the left hand. This end of the machine applies the load to the specimen. The function of the other end is to measure the magnitude of this load. A shackle G-, similar to F, is attached to the curved lever K, whose fulcrum is at L. A vertical link M connects the curved link K with the steel- yard N, the fulcrum of which is at O. Running on the steelyard is a trolley P, which carries weights of known magnitude (W). This trolley can be run along by a chain and hand wheel attachment. A scale, attached to the steelyard, registers the leverages, and serves as a means of calculating readily the magnitude of the pull on the specimen. Let W = magnitude of weight in pounds, and x = steelyard reading ; then the total pull on the specimen, when the lever is floating between the pins, Wxjc pounds. It will be noted from the diagram that, in order to cause the steelyard to float, the shackle G must be moved to the left. The two shackles F and G can be connected through the specimen, and, by pumping water into the cylinder, a pull can be transmitted from F to G through the specimen and accurately measured by W and its position on the steel- yard. When a specimen is being tested, water is pumped con- tinuously into the cylinder, and the weight W is run out at such a rate as will just keep the lever floating between the pins. When rupture of the specimen takes place, the position of the weight is noted, and the magnitude of the breaking load is then calculated. Results of Tests. — The first set of tests, as shown in fig. 2, were carried out by Prof. Stanfield in November 1912. The results obtained are unfortunately of little value for purposes of comparison, although many important points arise in connection with them. It will be seen that all the links are made of f in. material, and calculation shows that for a close link chain of this section the breaking load is 4*3 tons. Only one type of link gives a result approaching this value, namely, the D link. The application of any of the other types leads to this important conclusion—that the factor of safety on the chain itself is reduced very con- siderably by their use. Although differences exist in the breaking loads for the same type of link, it would be unfair to lay any stress on these discrepancies, since no informa- tion was available as to the quality of the material from which the various links were made, or yet of the history of their manufacture. This point was fully realised by those attending the tests, and was, in fact, put forward as a reason for carrying out further tests. The results, however, show conclusively the unreliable nature of all types of links fastened by small rivets. In all these links fracture invariably took place through the rivet holes, due, no doubt, to high local straining at these sections, a condition which will be considerably aggravated by the jerky working obtaining in colliery practice. One other point of extreme importance should be noted : in practically all cases where the cross section of the link material was reduced by tapering and punching, there was evidence of burning of the material. The reliability of the link is not governed so much by the structural design of the link as by the human element which comes into play in the manufacture of the link. It would almost seem to be advisable to avoid all types of links showing very small sections, unless the smith can be relied on to treat the material properly. The superiority of the D link is due both to its design and to the fact that the eye of the link is large and the change in section very gradual. In. both tests failure occurred by drawing the rivet heads, no part of the link being actually fractured. Later tests show that more efficient riveting caused fracture to occur at another point in the link; but it must not be forgotten that a larger rivet head is more liable to be worn off, and a point is soon reached when the strength of the link will begin to decrease, due to wear of the rivet head. In view of the unreliability of the foregoing tests, Mr. Paul, of the Lochgelly Iron and Coal Company, and Mr. Beveridge, of the Fife Coal Company Limited, both sent the writer sample links for tests, the links, in each case, being made from the same material and by the same smith. The results again show inconsistencies, but both sets of results prove conclusively the superiority of the D link, both in regard to strength and to reliability. From a general survey of all the results, it would appear that no one type of link is entirely reliable, and that the term “ false link ” is a very apt one. The discrepancies are not surprising, and are bound to appear as a matter of course in all types of links where forging and punching operations have to be performed on small sections. The bigger bulk of metal in the eye of the D link lessens the risk of damage to the material, and this fact, combined with good design, makes the D link a reli- able one. Against this there is the danger of the eye catch- ing on projections on the hutchway. Of the various riveted links, a well-made link of the type C lends itself readily to reliability, safety, and ease of manufacture. The discussion was adjourned. MINING AND OTHER NOTES. Sir Robert Turnbull, having ceased to act as general manager of the London and North-Western Railway, has resigned his position on the Railway Executive Committee, and has been succeeded on that committee by the new general manager, Mr. Guy Calthrop. Mr. Dermont Campbell, aged 58, of Crawford Park, Dunblane, managing director of the firm of Messrs. Jones and Campbell Limited, ironfounders, of Larbert, left personal estate in the United Kingdom valued at .£10,284. The report of the Comptroller of the Companies Depart- ment of the Board of Trade for 1913 states that according to the returns of the Registrar of Joint Stock Companies, the number of new companies registered in England and Wales during the year was 6,871; from which should be deducted: companies which have gone into liquidation, 1,938; companies removed from the register as no longer carrying on business, 1,035; net increase, 3,898. The number on the register on December 31, excluding companies which were in course of liquidation or removal from the register, was about 56,500. The number of companies on the registers in the United Kingdom on the same date was about 63,000. The number of cases in which winding-up proceedings were begun during 1913 is as follows :—Voluntary liquidations, 1,799; voluntary liquida- tions, subject to the supervision of the court, 10 ; compulsory liquidations, 137; total, 1,946. In one case of compulsory liquidation the winding-up proceedings were stayed, bringing the total down to 1,945. Mr. Robert Shaw, A.M.I.E.E., chief estimating engineer to Bruce Peebles and Company Limited, Edinburgh, has joined the engineer units of the Royal Naval Division for active service abroad, and as he will in all probability be away for some little time, Mr. William Oliver, B.Sc., A.M.I.C.E., has been appointed to temporarily fill Mr. Shaw's position with the firm. Messrs. Bruce Peebles announce that since the outbreak of hostilities well over 100 members of their staff and works have joined the forces. Mr. H. R. Griffiths has been appointed by the Great Western Railway Company as divisional superintendent at Bristol, in succession to Mr. Charles Kislingbury, who has retired after upwards of 40 years' service with the company. Mr. Griffiths has been Mr. Kislingbury’s assistant for 10 years. General meetings of the North-east Coast Institution of Engineers and Shipbuilders will be held during the present session on the following dates :—October 30, November 27, December 18, 1914; January 29, February 26, March 19, April 30, 1915. Meetings of the graduate section have been arranged for the following dates:—October 31, November 21, December 12, 1914 ; January 30, February 27, March 27, and April 24, 1915. Meetings of the Manchester Association of Engineers will be held on October 24, November 14, 28, December 12, 1914; January 9, 23, February 13, 27, March 13, 27 (annual meeting). Messrs, the Cambridge Scientific Instrument Company Limited ask us to state that they have taken over the business connection of the Leskole Company Limited, Palace Works, Enfield, who have gone into liquidation ; also that Mr. F. Wakeham, the assistant manager of the Leskole Company, has joined their staff. Messrs, the Selson Engineering Company Limited, 83 and 85, Queen Victoria-street, and Lambeth Hill, ask us to contradict the assertion that their company is a German concern. The company was registered in December 1909, and is a strictly British concern, both as regards capital and directorship. The company has works in both Coventry and Halifax, whilst the staff and workmen, with only two exceptions, are British. Besides the tools of their own manufacture, the company hold stock of a variety of American tools and machines for which they are the sole agents in this country. The departmental committee appointed to enquire into the working of the Railway Improvements (Prevention of Accidents) Act of 1900, has been adjourned sine die owing to the altered circumstances caused by the war. Mr. E. J. Reed, formerly sales manager to Messrs. Miles, Sykes and Son Limited, and for several years chief publicity writer to the British Westinghouse Company, has been appointed advertising manager to Messrs. Ed. Bennis and Company Limited, of Bolton, the well-known manufacturers of mechanical stoking apparatus, etc. The offices of the publicity department are at 28, Victoria-street, London, S.W.