August 14, 1914. ___________________________________________________________________________________________________ 366 THE COLLIERY GUARDIAN. giving visual indication to the winding engineman of the particular level or hanging-on place from which the signal is given. The apparatus is illustrated in figs. 1, 2, and 3, and includes a number of slides A (fig. 2), each of which presents on its surface a number denoting the order of the signal. The slides are so mounted in relation to an apertured dial that as the selected slide is actuated the figure is brought opposite the corresponding aperture. The slides are guided to move vertically, and receive actuation from a system of levers B (fig. 3), each of these slides co-operating with a pawl C, which serves to maintain the slide last to receive actuation in indi- cating relationship with the aperture. Each of these slides is formed with a cam surface, which in contacting with the pawl C releases the slide previously actuated, so that the latter is returned by gravity to its normal pbsition. The actuating levers B are mounted to move collectively, and are moved separately into engagement with the slide to be actuated, such movement being derived from a system of tappets D, which come into contact with the lateral edges of the levers B. The tappets are disposed helically on the cylindrical surface of a barrel E, deriving step by step movement from a pawl and ratchet F. It will be understood that the Fig. 1.—Front Elevation of Signal Indicator. Fig. 2.-Front Elevation, with Apertured Dial Removed. 5|6l7ffi j u I Im ■(F i' 111________M A ■ -Bid position of the tappets will be determined by the number of signal given, and that the figure on the slide will correspond to such number. The barrel is so loaded that it tends to return to its initial position. In order to prevent immediate return of the barrel to its initial position, and thus permit of the continuation of its step by step movement when several signals are given succes- sively, the ratchet is arranged to co-operate with a detent G, constituted by a loaded bell crank lever H, one arm of which receives actuation from a loaded cylinder. This cylinder acts to retract the detent G from engagement with the ratchet, and thus permit the barrel to return to its initial position, so that on receipt of a subsequent signal the indication will recommence from zero. From this description it will be understood that the figures on the indicator are not shown accumulatively— that is, for example, if 3 be signalled, and after a pause 1, the instrument would not indicate 4, but 1, as it is automatically arranged to extinguish the preceding signal. The indicator, which is entirely mechanical, and can be applied to existing bell arrangements with- out trouble, is thoroughly reliable in every respect. __________________________ MINING INSTITUTE OF SCOTLAND. A general meeting of the Mining Institute of Scotland was held on Saturday, 8th inst., in the rooms of the institute, 39, Elmbank-crescent, Glasgow. Mr. James Hamilton, Glasgow, the president of the institute, was in the chair. The following were admitted to the membership of the institute :—Messrs. George Higgins, coal master, Dumbreck, Glasgow; Robert McPhail, ’ assistant manager, Bog Colliery, Larkhall; John M. Martin, mining engineer, Carmyle, Glasgow; John O’Donnell, under-manager, Home Farm Colliery, Hamilton; Nicol Stevenson, mine manager, Queen’s County, Ireland; and as an associate member, Mr. R. L. P. Bell, colliery furnisher, Coatbridge. Mining Economics : Some Notes and a Suggestion. Discussion was afterwards resumed on the paper con- tributed by Mr. John Gibson, Kilmarnock, on ‘‘ Mining Economics : Some Notes and a Suggestion.” Mr. R. W. Dron, Glasgow, in the course of a written communication, said Mr. Gibson appeared to assume that the whole situation was dominated by the thrift- less men who were content to work three days per week. After all these formed only a small proportion, and the solid mass of the men were both thrifty and anxious to work. The provision of better housing, with a corre- spondingly higher standard of living, was undoubtedly a good thing from a social and economic standpoint, but it could only have an indirect effect on the economy of mining. The premium system of payment had always the disadvantage that it was almost impossible with the varying conditions of mining to fix a line which would not, in the long run, cause a permanent increase in cost. No doubt it was very easy to make some concession to a miner in the hope of getting better work, but it was very difficult to get back the concession when it was found that the better work was not being maintained. Mr. James Gilchrist, Cambuslang, said he agreed with the author’s method in levelling all main roads so as to get the proper gradient for carrying the mineral worked to the shaft bottom. He would suggest, how- ever, after the road had been levelled, and it had been decided what the gradient of the road was to be, that the manager should get the joiner to make a straight edge with the proper angle of the gradient on it, so that every set of rails would be laid down correctly. For many years past he (Mr. Gilchrist) had not found any better system, and the same method applied to either dip or rise mines ensured a properly graded road for any kind of haulage. He was sure they all agreed with the author of the paper that overcrowding in work- men’s houses was a great evil in more ways than one. While great improvements had been made in different branches of mining, few of them could point to much Fig. 3.—Eno Elevation, with End-plate Removed- improvement in regard to the housing of miners. Even to-day the best type of house which was being built was much short of what it ought to be. He favoured the provision in every colliery village of houses of three and four rooms, so that large families could be pro- perly accommodated, while there would also be suitable accommodation for lodgers. Mr. J. Balfour Sneddon, Mid-Calder, said that at the last meeting of the institute when this paper was discussed, Mr. Gibson seemed to be surprised at certain data which he (the speaker) had put forward. He inter- posed merely to remark that the data he had adduced was strictly accurate. The figures he submitted clearly showed that where the miners had the assurance of regular work they themselves acquired habits of steadiness in attendance at that work. Mr. Sam Mavor, Glasgow, said he thought there was a good deal in Mr. Gibson’s suggestion, that if the miners were better housed they would be compelled, as other tradesmen were, to work more nearly the full week than they did at present, in order to obtain money for the rent of their superior house. He thought it rather a pity that the general custom in the past had been to erect too many houses on the principle of miners’ rows. That ^system never encouraged individuality or initia- tive on the part of those who occupied them. Mr. James Hamilton, the president of the institute, remarked that Mr. Gibson’s paper was terse and con- cise to a degree that was very unusual in their Transactions. It raised many points in mining management from the economic side not too clearly understood nor sufficiently considered, and the manner of doing it was calculated to make readers pause at many points and ask if this was so. One of the prominent features in the paper was its generalisation. Generalisation was always tempting and always dangerous, and it seemed to him that the author had sometimes fallen into the pit dug by his own hands. There was one generalisation that would not stand examination, namely, ‘‘ the most backward coalfields are those with the least natural difficulties and most valuable seams.” Taking the Hamilton district of the Lanarkshire coalfield, Mr. Gibson would probably not dispute that that district had fewer natural difficulties and more valuable seams than Ayrshire generally, and he was no more likely to contend that Hamilton was more backward than Kilmarnock. Carrying the point further, let them compare, say, Newcastle and Durham of 30 or 40 years ago with South Wales of the same time. In order to justify his statement, Mr. Gibson should have assumed that his backward field, in addi- tion to being blessed, should they say, with few natural difficulties, could be exploited by men with small capital. The appropriate contrast would be the placer mining of a gold rush, and the gold mining of the Rand. It was not mere natural difficulties and value that counted — it was more the capital and organisation necessary to get the mineral. He said in the paper : “ It is the business of the coal owner to produce coal, not to house workmen.” But the coal owner must provide machinery to produce coal, and workmen would be an essential part of the machinery till Prof. Ramsay’s speculation of making the coal mine an immense gas retort was realised. If men were necessary then they must be housed as engines were housed. If Mr. Gibson’s reasoning was correct, the coal owner’s interests demanded that his workmen be provided with houses that were sanitary, and such as would raise the men’s cost of living. The Fife men were usually credited with knowing their own interests, and the Fife coal owners were now building high-class miners’ houses in the east of Fife, although the conditions there, if anywhere, favoured the leaving of the housing to private building enterprise. Mr. Gibson was sound in his reference to the economic output of a colliery, but he offered no suggestion towards the fixing of this. Presumably he meant it to be done from experience, but that method could not be easy, nor quickly carried through. The economic output necessarily varied from time to time under changing conditions. It was an ideal to be aimed at, not a condition to be reached and maintained. Though these criticisms were made, the paper was, nevertheless, a useful one. If education be a drawing out rather than a putting in, then the author’s paper would serve a truly educative purpose by stimulating thought, pro- ducing new ideas, and promoting the aims of the institute. Mr. Gibson said he would reply to the criticism offered to his paper in due course, and would endeavour to reconcile what the president held to be apparently irreconcilable. Sinking and Equipment of Blairhall Colliery, Fife. The discussion on the paper, “ Sinking and Equip- ment of Blairhall Colliery, Fife,” was closed, and the author, Mr. Archibald M. Russell, thanked for his paper. The Rosehall Signal Indicator. Mr. James Black read a paper on “ The Rosehall Signal Indicator.” (See previous page.) The discussion was adjourned till next meeting. Fan Testing, with Special Reference to the Measurement of Pressure. Mr. Thomas Bryson, Glasgow, read a paper on Fan Testing, with Special Reference to the Measurement of Pressure.” (See p. 375.) The. discussion will be taken up at next meeting. ____________________________ Rescue Apparatus in the United States.—According to a report by Mr. J. W. Paul, the United States Bureau of Mines has had under consideration and has conducted tests of the following types of breathing apparatus :— Essential agent. Compressed air... Compressed air... Fresh air........ Oxone .......... Oxone .......... Oxone .......... KNaO3 .......... Liquid air ....... Compressed oxygen Compressed oxygen Compressed oxygen Fresh air........ Fresh air........ Place of invention. United States. United States. United States. United States. United States. United States. Austria. Austria. Germany. Germany. England. Germany. Germany. Type of apparatus. Vajin Bader......... National helmet_____ Barnum's respirator... Merryman's respirator Servus ............. Hall's emergency ... Pneumatogen II...... Aerolith__............. Westfalia (Meco) ... Draeger............. Fleuss (Proto)....... Koenig ............. Westfalia........... The tests made resulted in the purchase for the bureau of a number of the Fleuss, Draeger, and Westfalia types of apparatus for use in mine recovery and rescue work, those types being the only ones available that meet requirements and local conditions. The compressed air types were found to be unsuited for use in poisonous gases, and the duration of their efficiency with one charge was insufficient for mine work. The types that generate oxygen by chemical means have so far proved objectionable on account of the slowness with which they liberate the required quantity of oxygen, and the high temperature and humidity of the regenerated air. No opportunity has as yet been offered for tests of the latest model of the Pneumatogen apparatus recently ordered. The liquid air type has meet the laboratory test requirements in so far that it is light, and furnishes a cool air and in sufficient quantity, but it has not been adopted for actual mine work because of inability to procure with any degree of regularity a supply of liquid air from the factories which are far removed from the mining centres. During the past two years so much trouble has arisen in the use of the helmet type that its further use is doubtful, the mouth breathing type proving more desirable. With the three types, Fleuss, Draeger, and Westfalia, the subjects have had no difficulty in performing their prescribed tasks uninterruptedly until the exhaustion of the supply of oxygen in the bottle. Some difficulty has been experienced from reducing valves failing to deliver the required quantity of oxygen. Upon testing new valves it is found that they furnish varying quantities of oxygen and at varying pressures, showing a lack of standardisation at the factory. At Mr. Paul’s suggestion, the Draeger factory has recently submitted two apparatus, one equipped with double reducing valves, which may be operated separately or in unison, and a second equipped with a by-pass valve for emergency use. The following constitute the breathing apparatus equipment of the Bureau : Draeger, 1904-7 type, 18; Draeger, 1910 type, 47; Draeger, 1911 type, 16; Draeger, j-hour type, 3; Westfalia, 36; Fleuss (Proto), 8; Aerolith, 5; Pneumatogen II., 1; Koenig Fresh Air, 1; Westfalia Fresh Air, 4; Hall’s Emergency, 30—total, 169. There are now installed at mines in the United States about 1,000 breathing apparatus, principally of the Fleuss, Draeger, and Westfalia types. Private rescue training stations have been equipped for training and emer- gency work in several of the States, and seven railroad cars for such work have been put in service by different mining companies, and three by the State of Illinois. The advis- ability of training with compressed air in the oxygen bottle and discharging the exhaled air to the atmosphere to avoid the expense for upkeep for oxygen and regeneration ia suggested as a subject for discussion and advice.