February 21, 1913 THE COLLIERY GUARDIAN. 401 Table 4c (See previous page). Coal number. 1. 2. 3. 4. 5. 6. 1 gramme* ( 0*19 gramme per square centimetre 7 3*041 9’981 7’511 6*201 7’561 7*711 3’10 >3*05 3*003 10*03 > 10*03 10*09 ) 7*53 > 7*52 7*523 6*13 >6*19 6’243 7*47 > 7*51 7*513 7*87 >7*78 7*773 1’5 gramme* ( 0*26 gramme per square centimetre < 10*16 7 ,n., A 10*13 |10 14 7'69 7 7*58 J 7 63 6’00 7 k.qw 5'94 j 7*53 7 7*60 ) ( 56 7*83 7 ™ 7*83 ) 7 83 5 grammes f 7 0*16 gramme per square centimetre ) 2*98 9*94 7’53 6*08 7*53 7*77 ■ 7*5 grammes f 7 0*25 gramme per square centimetre ) 3*00 10*02 7'76 6*15 7*60 7*85 Average 3*01 10*03 7*61 6*10 7*55 7*81 * Weighing bottle 50 to 70 millimetres high and 27 millimetre diameter; cross sectional area = 5'7 square centimetres, f Weighing bottle 30 millimetres high and 60 to 63 millimetre diameter; cross secti >nal area = 30*4 square centimetres. 40—50 grammes of coal (100 grammes of coal of low water content) are weighed into an Erlenmeyer flask of 500 cc. capacity, 200 cc. of xylene are added and 150 cc. of this are distilled over, the flask being heated on a sand bath, into a measuring cylinder the lower part of which is divided to cc. The measuring vessel is then hung in a cylinder with warm water. Any drops of water which hang about the shoulder of the measuring vessel are detached and allowed to fall to the narrow part by means of a glass rod. After one hour standing, the volume of the water distilled over with the xylene and which has separated under it, is measured, due correction being made for the meniscus. The results obtained are given below: Coal No...... 1. 2. 3. 4. 5. 6. 3’00 ... 10’38 ... 7’80 ... 6*16 ... 7'74 ... 7’60 The method is ingenious and, in the opinion of the reporters, has many advantages and might be well made the subject of further trial by other workers. (To be continued). Letters to the Editor. The Editor is not responsible either for the statements made, or the opinions expressed by correspondents. All communications must be authenticated by the name and address of the sender, whether for publication or not. No notice can be taken of anonymous communi- cations . As replies to questions are only given by way of published answers to correspondents, and not by letter, stamped addressed envelopes are not required to be sent. ANALYSIS OF THE BERESFORD SEAM. Sib,—I am sorry to say that in the analysis of the Beresford coal published by you, which was taken from an uncorrected proof handed to your repre- sentative, there are three errors, as per corrections here- with. The amended figures, you will observe, add 600 lb. to the sperm, and the sulphur in the coke works out to 0*41 per cent., which compares with 1*04 per cent, for the Wharncliffe Silkstone gas coal. Castle Hill House, Dover, A. E. Ritchie. February 17, 1913. [The analysis of the Beresford seam at the Snowdown Colliery appeared in our issue of the 14th inst., p. 332. With the corrections now made, “ the value of gas from one ton of coal in sperm ” should read 717*98 lb. (instead of 117*98 lb.); the “ sulphur eliminated with volatile products,” 9 85 1b. (instead of 6*27 lb.); “sulphur in coke per ton of coal,” 6*27 lb. (instead of 9'85 lb.).— Ed. C.GJ]___________________________ THE STATUS OF COLLIERY SURVEYORS. Sib,—I regret that the main point of my letter, dated November 6, 1912, and of that from Mr. O’Donahue and myself, which you were good enough to publish on the 24th of last month, appears to have been somewhat overlooked. No suggestion has been made, either by myself or Mr. O’Donahue, for mineral surveyors to associate themselves with the Surveyors’ Institution as at present constituted. I quite recognise that mineral surveyors must decide for themselves on this matter, but it would be a great pity if this opportunity of being recognised by an old established institution of unques- tionable repute were lost. Any movement for the formation of an independent society in Wales does not affect the question. If they in Wales desire such a society, and can form one locally they surely are at liberty to do so. However, I have no doubt that when the larger question at issue, with its many obvious advantages, becomes generally known, the general body of mineral surveyors will respond to the appeal of Mr. O’Donahue and myself, and enable us again to approach the council j of the Surveyors’ Institution, so that they may feel justified in setting up this additional subdivision. There are many difficulties in the way of forming an independent institution, the most apparent being the cost of management. Again, it would be many years before a new institute became firmly established and recognised in the country, whereas those passing the examination set under the subdivision No. 4, already referred to, would at once have the benefits of an already established institution, which, to quote Mr, Cooke, is a “ well-organised and powerful one.” Mr. O’Donahue and myself have considered, with the council of the Surveyors’ Institution, the question of an examining board, who would represent all branches of coal and metal mines surveying, ensuring a truly representative examination. Regarding the statement that membership of the Surveyors’ Institution is the hall mark of the profession, I would state that this is surely evidenced by the Government being largely influenced in filling the various appointments under the Finance Act by appli- cants being members of the institution. The surveying examination as set by the new Mines Board should, as stated in my letter of November 6 last, ensure a more reliable colliery surveyor, but there are many appoint- ments in the surveying profession, particularly in the colonies, which call for a much higher standard. Membership of the Institution of Mining Engineers does not necessarily ensure a thorough knowledge of high-class surveying. I am not a member of the Institution of Mining and Metallurgy, but I assume that before anyone can become a member they must possess a thorough knowledge of more subjects than surveying. I do not question the qualification of members of the Institution of Mining and Metallurgy. Speaking from personal experience as a mining engineer in the Colonies, I came in touch with a class of highly qualified surveyors, who, graduating from the Royal School of Mines, were members of this institution, but they had many other qualifications than surveying, otherwise they would never have been admitted. This is just the pith of the whole matter; mineral surveyors at present have no recognised institution chiefly devoted to the science of high-class mine surveying. A syllabus of subjects and examples of the papers set at preliminary and professional examinations, is issued by the Surveyors’ Institution for the sum of Is. 6d., and if those interested in this matter will obtain this syllabus they will form, as “ H. B.” suggests, a fairly accurate idea of the nature of the examination likely to be set on mine surveying. I, therefore, again ask that if the forming of sub- division No. 4, chiefly mineral surveying, by the Surveyors’ Institution, appeals to those interested in surveying coal or metal mines, they communicate with either Mr. O’Donahue or myself, or, as indicated in our letter of the 22nd ulto., with the secretary, 12, Great George-street, Westminster, S.W. W. H. Galletly. West Riding and Silkstone Collieries, Normanton. February 18, 1913. Sib,—As a student who is “ wasting ” time and money in obtaining a diploma in mining and surveying, I feel impelled to answer some of the statements in “LI. B.’s ” letter in your issue of the 7th inst., and to dispute his facts. It is doubtless a good suggestion to form an institute of mine surveyors, with its own laws and governing body, admission to be either by certificate, as under- stood by the Home Office, or the production of some evidence of practical ability to act as a mine surveyor. I should like, however, to remind “ LI. B.” that the certificate granted by the Home Office, if it be the “ hall mark ” of the acting mine surveyor, is not ‘ demanded of a man who is the possessor of a diploma ! in mining and surveying granted by an approved . university or mining school, such diploma being con- I sidered as equivalent to the Home Office examination. In spite of your correspondent’s somewhat emphatic statements, I beg to submit, with all due deference, that he is either extremely ignorant of the curricula of a university or mining school as approved by the Home Office, or else wilfully blind to facts. One is compelled to this view when considering the substance of his statements, in which it is inferred that the gaining of a diploma simply represents— (1) A sum of money expended. (2) The cramming of formulae, useless, except as mnemotechnics. (3) That the time spent in such training is wasted, because half of the subject matter is of no practical use after the “ test.” (4) Further, that our time could be better spent in the reading of mining journals, etc., and in training our minds along lines which will be of practical use in our daily work ultimately. Categorically I submit that the foregoing statements in fact and substance, except the first, are quite untrue. I quote from the syllabus of my own college and my own experience. The student, to obtain the diploma, must give evidence by practical work, besides a quite secondary theoretical examination, as follows:— (а) The student is required to make an accurate survey of a colliery or portion of a colliery, using either the miner’s dial, or any type of theodolite, and be capable of adjusting the latter. (б) A section of levelling on the surface and under- ground with the Wye or dumpy level, also testing and adjusting such an instrument. (c) Make an accurate connection of underground and surface surveys. (d) Complete a triangulation survey with the theo- dolite. (e) Set out works maintaining alignment, and gradient curve ranging. (/) Prepare plans and sections of the foregoing, including plotting by rectangular co-ordinates. The so-called useless formulae would be required in the intelligent reduction of observations, calculation of co-ordinates, mathematically solving one’s triangulation, corrections for errors. Also for the estimation of coal and ore reserves, content of earthworks, capacity of reservoirs, &c. As to “ LI. B.’s ” third indictment, I submit that none of the time spent in the foregoing is “ wasted.” Further, I find I am compelled to put in a minimum of four months’ practical work underground, and, in my own case, granted facilities for attending and taking active part in the quarterly surveys at the colliery to which, during any period of training in college, I am attached. Is this time “ wasted ” ? It must be remembered, it is all part of the much despised diploma course. I also submit that the subject matter is all relevant to practical work, and the test essentially a practical one. Thus, one’s future work merely becomes the further application of practice already acquired. As to his last statement. Incidental to the above we are studying mining, with particular reference to coal mining, and have the advantage of the notes of lectures and practical geological work under a professor with a practical knowledge of the coalfields of Great Britain, and a particular notion of the requirements of mining students in general. This demands the reading of the literature of the day in the sciences of mining, surveying, and economic geology, and mechanical engineering as applied to mining. Surely, this is an attempt at improving our knowledge in the work of mining ? I therefore maintain, Sir, that the statements of “ LI. B.” are not in accordance with facts. Also that a man equipped in the way I have indicated is a fit person to be placed in the same category as those who bear the Home Office “ hall mark of their profession ” without a diploma, or by virtue possibly of some years of service with nothing but a miner’s dial. Brynheulog, Habold V. Hinton. Forrest Road, Penarth Lower. February 13, 1913. THE PREVENTION OF EXPLOSIONS. Sib,—I am much obliged for the long review of my book in the last issue of the Colliery Guardian. It is true that the “ expert ” (I presume it is an expert who wrote it) is a trifle hostile, but as I have been very busy pulling “ experts ” inside out for the last two years I don’t expect to get sugar in return. Rather a pity