February 26, 1915. THE COLLIERY GUARDIAN. 451 LINNEKER AND ADAMS’ MECHANICAL BELL CANCELLING GEAR FOR VISIBLE SIGNALS. At the Micklefield Coal and Lime Company’s pits in Yorkshire an ingenious signalling accessory has been at work for some time, and is stated to have given com- plete satisfaction. This is Linneker and Adams’ patent automatic cancelling gear for visible signals at mine shafts, etc., which is made by Messrs. E. C. Theedam Limited, of Dudley. As shown in fig. 1, the gear is attached to a self- registering dial, and does not come into operation until the whole of the intended signals given are registered on the dial plate. Then, by means of a lever A, which Can be set to cancel the signal at any desired point of the wind, and is controlled by a simple small atmospheric air pump F, the next signal given wipes out the previous signals, and at the same time registers the new signal. The pointer recording the signal given is turned by the catch -0; B indicates the pull coming up the shaft or from the pit bank, as the case may be; while G is a rod that works the atmospheric plunger K in the atmo- spheric chamber F. All the signals remain on the dial until the one is given which is intended to remove the previous signal. Messrs. Theedam Limited have recently put on the market several other useful signalling devices. One of these is an electrical indicating signal apparatus, shown in fig. 2. This operates with a pawl and ratchet wheel worked by an electro magnet, which strikes the bell gong, and indicates step by step the signals given on the dial. A -small electro-magnet is fitted for releasing the pointer back to zero. This can -be operated from any desired contact, and from the contact box described below. The dial is vitrified enamel, and numbered zero to 10, size 17 in. by 4| in. The case containing ■B ■ i » , J E * s t. Fig. 1.—Patent Automatic Cancelling Gear. Fig. 3.—Contact Box mechanism is of polished oak, 7|in. by 10in. by 11| in., fitted with a door, lock, and key, -so that the apparatus can be easily tested and examined when required. To work the indicating bell, a special ringing key is supplied with a contact box, specially designed to meet the requirements of the General Regulations for signalling when winding men, so that the signals 3 can be given, and the hand flies back to zero, before the signal 1 or 2 can be given, thus making it impossible to give one signal on the top of another unless done wilfully. The front of the ringing key is fitted with a small radial arm, which is brought back to the neutral posi- tion by a spring. The lever A.C. is turned round till it comes to B, and then the signal is given by pressing it down as with an ordinary ringing key. The operation of this contact is, that when the small arm is pushed over, and before the actual ringing contact is made, a connection with an electro-magnet in bell case releases the indicator, which flies back to zero before another signal can be given. The ringing key itself is of the frog Morsepateern, gas and waterproof, in cast iron case with steel contact -springs fitted with gold-silver rubbing contacts and line terminal, mounted on ebonite base. We understand that the Home Office have intimated that these bells and the cancelling arrangement carry out the requirements of the Coal Mines Act. COAL AND ITS RELATION TO THE PHARMACIST. On February 15, a lecture was delivered by Mr. J. F. Simon, Ph.C., M.P.S., before the Sheffield Pharmaceutical and Chemical Society, on “ Coal, Coal Tar, and its Relation to the Pharmacist.” The lecturer dealt with the geological formation of coal and the various processes from which its derivatives are obtained, illustrating his remarks by a series of lantern slides and by specimens of the different products. He said it was interesting to note that in the utilisation of sulphate of ammonia, we have an example of a complete cycle, viz.:— __ . ,, , r Ammonia J V egetable Kingdom\ — Sulphur Dioxide— • — Coal Sulphuric Acid j Sulphate of Ammonia—Vegetable Kingdom. The lecturer spoke of the use of coal tar products for medical purposes. He said the employment of synthetic coal tar products m internal medication might be said to date from the introduction of kairin, a synthetic substitute for quinine, discovered by O. Fischer in 1882. The unsatis- factory results and difficulties encountered caused a lapse of interest, until the accidental discovery of the antipyretic properties of antipyrine in 1885, and acetanilide in 1888. The simplicity in structure with the valuable medicinal properties attracted the attention of pharmacologists and chemists, and afterwards new and valuable products began to follow in quick succession, and to-day an enormous number was on the market. In the fractional distillation of coal tar, the distillate passing over from 80 degs. to 110 degs. Cent., consisted of benzene and toluene, which were both extremely important to the manufacturing chemist and to the retail chemist also. Benzene is the source of many ordinary chemicals which are in everyday use, a few of which are:—Acetanilide, exalgin, phenyl hydrazine, antipyrine, salts of antipyrine, such as acetopyrine, salipyrine, resopyrin, hypnal, butypnal, pyramidon, ferripyrine, migrainine, atoxyl, pyrogallic acid, phenacetin, thermodin, benzaldehyde, benzoic acid, &c. Toluene is the starting point for the production of saccharin, sucramine, &e. From the fraction of coal tar distilling over between 170 degs. to 230 degs. Cent., (1) naphthalene, (2) crystalline carbolic acid (pure), (3) liquid carbolic acid (impure), are obtained. Naphthalene is the source of alpha and beta naphthols—alphol, betol, benzo naphthol. Pure crystalline carbolic acid yields sodium salicylate, diuretin, acid salicylic, methyl salicylate, salol, acid aceto salicylic (aspirin, xaxa, coxpirin, salaspirin, &c.), and the various salts—acid, aceto, salicylic, &c., picric acid, &c. Liquid impure carbolic acid (ortho, meta, para cresols), (1) mixed with fats and resins and then saponified, yields creolin, hysol, creosolin, cyllin, &c.; (2) cresols, being sulphonated or acetylated and then saponified, yield solved, sanatol, kresilfol, kresin, &c. The chemicals mentioned are only a few of the known and ever-increasing synthetic coal tar products. In conclusion, Mr. Simon urged the English manufacturing chemists at this opportune time to master the ever-increasing study of coal tar and its products. England was in no way less fitted for this fine chemical industry than Germany, and the wresting of Germany’s supremacy from her is simply a question of application and enterprise. Institution of Mechanical Engineers.—The annual report of the council for 1914 shows a net increase of 30 members and 92 associate members, against which has to be set a decrease of two associates, 65 graduates, and one honorary member. The total membership is now 6,400. The total revenue for the year was £16,970 15s. 8d., while the expen- diture during the same period was £15,521 9s. The total capital of the institution amounts to £69,273 5s. 4d. The first awards of the “ Thomas Hawksley ” gold medal, for the best papers published in the Proceedings of 1913 and 1914 respectively, have been made to Mr. Robert S. Whipple, for his paper on “ Modern Methods of Measuring Temperature ” ; Prof. Edouard Sauvage, for his paper on ‘ ‘ Recent Development of Express Locomotives in France ’ ’; M. Anatole Mallet, for his paper on “ Compound Articulated Locomotives.” The design of the medal will include a portrait of the late Mr. Thomas Hawksley. The fourth award of the water arbitration prize has been made to Prof. A. H. Gibson, D.Sc., for his papers on “ The Design of Volute Chambers and of Guide-Passages for Centrifugal Pumps,” and “ The Resistance to the Flow of Brine Solu- tions through Pipes.” The Benevolent Fund, which has been incorporated for nearly a year -and a-half, has not increased in the way that it was hoped would be the case. The total donations at the end of 1914 amounted to only Fig. 2.—Electrical Indicating Signal Apparatus, showing Inside Working Parts. £5,467 towards the proposed capital sum of at least £10,000; and the annual subscriptions amounted to only £251. The work of the Alloys Research Committee has been progressing at the National Physical Laboratory, but one of the assistants dealing with the research has been called out on active service in connection with the war. It is expected that the 11th report will be ready for presenta- tion during 1915. The Wire Ropes Research Committee appointed in 1913 has held three meetings, under the chair- manship of Mr. Walter Pitt. A schedule of 40 questions relating to the actual life history of a wire rope has been prepared, and copies -issued to representative large users of wire ropes, resulting in over 200 life histories being received for the consideration of the committee. Thirty-four sample portions of rope (worn and unworn) have also been received. It is hoped that the study of these data will indicate a useful direction for carrying out some tests upon a specially designed oscillating machine which is now under the consideration of -the committee. A Research Committee, with Capt. H. Riall Sankey as chairman, has been appointed, with the following reference : “ To report upon what experiments relating to ‘ The Action of Steam Passing through Nozzles and Steam Turbines ’ could with advantage be undertaken.” A large number of abstracts and other data have been prepared and considered by the committee, which has reported that experiments on the subject are desirable. This report has been accepted by the council, and the committee has been re-appointed to carry out the research work on the lines suggested. A Reseach Com- mittee was appointed to report on “A Hardness Test for Hardened Journals and Pins.” This committee, under the chairmanship of Dr. W. Cawthorne Unwin, F.R.S., has considered the known methods of testing for hardness by scratch, rebound, indentation, and abrasion, and has obtained from various manufacturers of steel balls and others, particulars of their individual practice. Some -tests have been made by Dr. T. E. Stanton, F.R.S., on speci- mens of steel supplied by Sir Robert A. Hadfield, D.Sc., D.Met., F.R.S., and other experiments are under consider- ation. The proposal to form a General Engineering Research Committee was discussed in February at a con- ference of the council, with representatives of universities, scientific societies, and large British engineering firms. An advisory committee, appointed to prepare a scheme for the co-ordination of research, is obtaining from manufacturers and others concerned their views on the subject.