228 Reviews—Notes on Geological Map-reading. 
detail than previous restorers of Paleozoic lands in Northern Europe, 
and has accordingly made a marked advance in this study. All 
students of the Palsozoic rocks should read his paper. 
J. EH. M. 
Notes on GeonocicaL Map-reapine. By A. Harker. 63 pp. 
Heffer & Sons. Cambridge. Price 3s. 6d. 
‘| [ies very modest title of this book does less than justice to its 
contents, for in spite of its brevity it manages to cover most 
of the ground in a thorough way, and is likely to find a wide 
distribution as a class book. The author begins with a very clear 
exposition of the meaning of topographical maps, and the way in 
which they serve as the basis for geological maps, taking the 6 in. 
Ordnance map as a type. He goes on to consider the simpler forms 
of geological maps and the various operations required in their 
interpretation. The argument passes on to unconformable series 
and then to faults. Folded strata of different degrees of complexity 
then receive attention, and a systematic method of constructing 
sections is described. The point is well emphasized that sections 
are merely illustrations, and cannot take the place of the map itself, 
and that the student must be able to interpret a map without 
having to reduce it to sections. Cases of all reasonable complexity 
are actually illustrated and explained. 
One can find nothing but praise for the order of treatment and for 
the general lucidity of the explanations. The method of using 
gradients for dip problems instead of vertical angles will be welcomed 
by teachers, especially those who are accustomed to use graphic 
constructions dependent on the accuracy of a rough protractor. 
On the other hand, the figures call for criticism. From the 
student’s point of view they are far from clear, and one or two are 
liable to confuse rather than to aid the text, as, for instance, the 
diagram showing the relations between strike, slope, and outcrop 
(p. 17). One feels that the book would have been much improved 
by a few block diagrams in illustration of the maps or of imaginary 
types of landscape. The maps themselves are models of clearness, 
but students will find it advisable to colour them before attempting 
to interpret them. 
All geologists will welcome this small book, but will wish that it 
had been expanded into a manual and were illustrated with 
more care. 
SOUTHERN RHODESIA: THE GEOLOGY OF THE ENTERPRISE MINERAL 
Bett. (Bull. No.7.) By H.B. Maure. pp.52andmap. 1920. 
We chief mining camp of the area examined is Arcturus, situated 
22 miles due east of Salisbury, and at an elevation of 4,600 feet. 
Highly folded schistose greenstones and sedimehts form a complex 
(the Basement Schists), almost surrounded by granite, of which there 
