Rankine's Manual of Civil Engineering, the figures elucidating the text have been specially drawn for this book. The Appendix of examination-questions and exercises for plotting has been culled from recent papers set at the examinations of the Science and Art Department, of the City and Guilds of London Institute, of the local boards under the Home Office for granting certificates of competency to Colliery Managers, and of various Mining Schools. These will, it is trusted, be found of use to such students as have not the advantage of regular instruction in the subject. It must, however, be borne in mind that the mere reading of a text-book will never make a minesurveyor. The most that a book can do is to help the student to obtain a knowledge of the theory of the subject. The mechanical manipulation of the instruments can only be learnt under the personal supervision of a teacher, whilst the technical skill requisite for carrying out subterranean surveys must be obtained in the mine itself. I have taken for granted on the part of my readers an elementary knowledge of mathematics, such, for example, as would enable them to pass the second stage of the Science and Art Department's examination in that subject. In the preparation of the work, I have received valuable help from numerous friends at home and abroad. In particular, I am indebted to Mr. H. W. Hughes, Assoc. R.S.M., F.G.S., for several important additions to the text, and to Mr. A. Pringle, M.A., B.Sc., who ably assisted me while the volume was passing through the press. THE ROYAL SCHOOL OF MINES, LONDON, February, 1888. BENNETT H. BROUGH. SURVEYING WITH THE MAGNETIC-NEEDLE IN THE PRESENCE OF IRON. |
