vi PREFACE TO THE FIRST EDITION 
make a geological survey of any district. Intending pro- 
fessional men will be ill-advised, however, if they do not take 
the trouble to understand the methods of observation 
employed in Field Geology, for such knowledge will often be 
of considerable service in their future careers. To mining 
and civil engineers, especially, an acquaintance with the 
methods of geological surveying and map-construction cannot 
fail to be invaluable, while agriculturists and public health 
officers ought assuredly to know enough of the subject to 
understand and interpret a geological map. I may be 
allowed to add that at the University of Edinburgh we have 
found no difficulty in teaching Structural and Field Geology 
to mixed classes of students of pure and applied science. 
The present Manual may be said to cover the ground gone 
over in our Summer Course of Geology—a course instituted 
some twenty years ago to meet the requirements of students 
desirous of obtaining a fuller knowledge of Practical Geology 
—more especially field-work—than could be presented in the 
seneral systematic course given in winter. 
The Plates which illustrate this volume have been derived 
from various sources. A number are reproduced from 
unpublished photographs taken by Mr R. Lunn for H.M. 
Geological Survey. Permission to use these was obtained 
from the Board of Education through the kind offices of Dr 
Teall, Director of the Geological Survey, and Dr Horne, 
Assistant Director. No one can be more sensible than 
myself that these illustrations give an interest to this work 
which it would not otherwise possess. To my former 
colleague and lifelong friend, Dr Peach, I am indebted for the 
coloured section which accompanies one of these plates. 
Plates X. and XXIV. are reproduced, by the courteous permis- 
sion of the Controller of H.M. Stationery Office, from published 
memoirs of the Geological Survey. My friend and former 
assistant, Dr Flett, now of H.M. Geological Survey, was good 
enough to supply me with the photograph reproduced on 
Plate XX XI., as well as with others which only the limited scope 
of my book has prevented me using. I am also under many 
obligations to him for reading some of my proof-sheets, and 
making various helpful suggestions. To another friend and 
former pupil, Dr Laurie, I am similarly indebted for the 

