Some Books on Geology. II9 
modes of accumulation, clays of commercial importance, clay-substance, 
theoretical and actual, and a bibliography. In non-technical language 
the book gives a good account of the nature and importance of clays, 
pottery, etc. It is also printed by John Clay. We cannot say whether 
the smooth surface of the paper on which it is printed is due to clay or 
not, though that material certainly plays an important part in the manu- 
facture of glazed art papers. A good proportion of the few illustrations 
refer to Yorkshire, and two are from The Naturalist. 
Building Stones and Clays, their Origin, Characters, and Examination, 
by E. C, Eckel. New York: J. Wiley & Sons;' London: Chapman & 
Hall, xvi.+264 pp., 12s. 6d. net. Almost simultaneously with Mr. Searle’s 
volume which refers to English clays and English methods of dealing 
with them, appears Mr, Eckel’s work, covering similar ground, but based 
upon American materials and American experience. ‘Tis interesting to 
compare the two. Mr. Eckel, however, is comparatively brief in his 
remarks, as he also deals with building stones, sandstones, limestones, 
igneous rocks, etc. The author has written memoirs on cements, 
for the United States Geological Survey, and is well known from his 
practical knowledge of the subject with which he treats. He pays special 
attention to the valuation and examination of clays and stone properties. 
There are also extensive lists of memoirs, etc., bearing upon the various 
subjects dealt with, to which the student may make reference. 
Geological and Topographical Maps: their Interpretation and Use. 
A Handbook for the Geologist and Civil Engineer, by A. R. Dwerryhouse. 
London: Edwin Arnold, 133 pp., 4s. od. net.—Dr. Dwerryhouse and his 
work need no introduction to our readers. His training at the Leeds 
University, at which field geology is so prominent a feature, and his 
subsequent work in the north of Ireland, have enabled him to write 
with authority on maps and mapping, a subject by no means so easy 
as it looks. In his preface warm thanks are proffered to Professor Kendall, 
who has been the means of so many taking up the study of geology with 
enthusiasm and good result. Briefly, Dr. ‘Dwerryhouse explains how the 
most information may be obtained from the Government geological and 
topographical maps, how they may best be read, what information they 
convey, how to draw maps, etc. Anyone engaged in practical field work, 
whether geological or engineering, will find the volume indispensable. 
We will admit that one or two of the illustrations are not quite clear to 
us, but that may not be the author’s fault. 
The Origin of Earthquakes, by Dr. C. Davison. Cambridge University 
Press, pp. vili.+144, 1s.—We are glad to draw attention to this fascinating 
account of earthquakes from Dr, Davison, whose paper on Yorkshire 
earthquakes, which appeared in this journal, will be remembered by our 
readers. He naturally lays particular stress upon the lessons to be learnt 
from Japan, California, and India in regard to earthquakes, but he also 
has much to say about those which have occurred nearer home, as at 
Derby and Carlisle. There are a number of illustrations showing the 
effect of earthquakes upon the landscape, some of which are remarkable, 
A Geological Excursion Handbook for the Bristol District, by S. H. 
Reynolds. London: Simpkin, Marshall, etc., & Co., 224 pp., It is” 
always a pleasure to see a well- illustrated and ‘practical geological guide 
to an interesting area, especially when it is written by someone particu- 
larly well acquainted with the different features of that area. Professor 
Reynolds’s volume well describes the various geological phenomena in 
the district around Bristol, and the plan might well be copied in other 
areas. The volume also contains a charmingly -written ‘ Introduction ’ 
by Professor Lloyd Morgan, 
1913 Feb..1. 
