of Coal Mining, and by the Special Rules in force in any given district.

The Author is well aware, after twenty years' experience, that the best and indeed the only satisfactory preparation for the efficient discharge of the duties of the Colliery Manager is that which is to be gained in the laborious school of experience; but he knows also that the wise use of a carefully prepared and comprehensive HANDBOOK-such as he ventures. to believe the volume now in the reader's hand will be found to be-would have been to him an incalculable boon in the earlier years of his course, and hardly less so subsequently as a book of reference and of practical guidance. No doubt excellent handbooks already exist, dealing with various branches of the subject; but the Author's aim has been in the following pages to prepare a work more complete in itself than any of its predecessors, and one comprising the most recent information as to the ever-progressing science and art of Coal Mining.

In the use of the work by students, it is believed that the questions and answers given on the various subjects will be found specially helpful.

The Author gratefully acknowledges the assistance which has been given him in preparing this work for the press by his friends Mr. J. T. Robson, H. M.'s Inspector of Mines for South Wales, and the Rev. J. E. Flower, M.A., of Wandsworth; and also the courtesy shown by the Council of the Mining Institute of Scotland in granting him permission to quote the result of their Commission of Mining Engineers, as given in their Transactions (vol. iii., pp. 51 to 124). Besides much valuable information which has been obtained from the Transactions of the North of England and South Wales

Institutes of Mining Engineers, he has also received considerable assistance from the columns of the Practical Engineer and the Colliery Guardian, and from other sources, reference to which will be found in various pages of the work.

The greatest care has been taken to ensure accuracy in every respect, but if any mistake has escaped notice the Author will be thankful to have it pointed out to him.

The preparation of this HANDBOOK-which for several years has occupied such time as the writer has been able to give to it has been to him a most congenial task; and he ventures, in sending it forth, to express the hope that the work may be found as useful to the student, and to those engaged in the management of collieries, as the preparation of it has been pleasant and profitable to himself.

PONTYPRIDD,

January, 1891.

PREFACE TO FIFTH EDITION.

THE two impressions of the Fourth Edition which were required having been disposed of, and disposed of, and a fresh edition being called for, the Author has again availed himself of the opportunity to revise the whole work in order to bring it in every respect up to date.

Besides the important addition (involving about 80 pages, with 30 new illustrations) which was made to Chapter XII. in the Fourth Edition, owing to the special attention of the Author having been directed to the subject of Mine Ventilation and the use of Regulators in Airways, further and even more extensive additions have now been made. These extensions cover in the main the fuller treatment now given to the subjects of Pumping Machinery, Rock and Coal Drills, and Coal Cutting Machinery; the latest developments of Safety Lamps have also received full and detailed attention; and the result of the revision and additions thus carried out is the further enlargement of the volume by about 230 pages, and the addition of as many as 300 new illustrations.

It will be noticed that some irregularity occurs occasionally in the numbering of illustrations, owing to changes (including both omissions and additions) made while the present edition

was passing through the press. Where any repetition of numbers occurs, the numbering is rendered distinctive by letters of the alphabet affixed to each repeated number-as, for example, in the case of Figs. 64A, 64в.

The Author may be permitted to remark that a work involving so many details, and sharing his attention with other engrossing duties, can hardly be expected to be wholly free from errors, although unremitting and scrupulous care to avoid error has not been wanting. He will be grateful, therefore, to be informed of any mistakes which may have escaped notice. He may be allowed to repeat here the thanks already expressed to correspondents who have done him the kindly service of apprising him of matters in the existing text which they deemed to require attention or suggesting new points for consideration.

He has also to acknowledge his indebtedness for material he has had the opportunity of adapting for the purposes of the present volume, from Mr. Stephen Michell's valuable treatise on "Mine Drainage," and the equally useful volume by Messrs. Arnold Lupton, G. D. Aspinall Parr, and Herbert Perkin, on "Electricity as applied to Mining."

CHEPSTOW,

July, 1904.

ERRATA.

Page 893.- In third line of the third paragraph, the words "shown in Fig. 773," should be omitted.

Page 939.-In second line of the second paragraph, instead of the words "carbonic anhydride," carbon dioxide."

read "