4 NATURE 
HIGHWAY ENGINEERING. 
Elements of Highway Engineering. By Prof. 
A. H. Blanchard. Pp. xii+514. (New York: 
J. Wiley and Sons, Inc.; London: Chapman 
and Hall, Ltd., 1915.) Price 12s. 6d. net. 
Bhs rapid development of mechanically pro- 
pelled road vehicles during the past twenty 
years has brought about a complete revolution 
both in the construction and maintenance of roads, 
and the question of the development of the public 
road system has again, after years of neglect, 
become a problem of natio1al importance. Motor 
vehicles are no longer mainly used for pleasure 
purposes; they are now an indispensable adjunct 
to almost every business, and for the economical 
working of motor lorries good road surfaces, and 
roads correctly laid out in regard to grade, are 
indispensable. Mr. Blanchard’s book, which has 
been written as a text-book for engineering 
students as well as a reference book for engineers, 
is a welcome addition to the literature of this 
branch of engineering practice. 
The first three chapters are devoted to an his- 
torical review of the subject, to a brief account 
of the systems of road administration in Europe 
and the United States, and to the preliminary 
investigations which must be made before an 
engineer can design satisfactory and economical 
highways. The fourth chapter treats of the neces- 
sary survey work in laying out urban and 
country roads, and of the preparation of the plans. 
The next chapter is devoted to the problems of 
grading, drainage, and, most important of all, to 
the question of the foundations upon which the 
roadway is to be carried. 
Earth roads, gravel roads, and broken-stone 
roads are then dealt with in order; the methods 
to be adopted in the construction of each class 
are described, and the question of maintenance is 
fully discussed. In the chapter on broken-stone 
roads the author explains in detail the modern 
methods of testing the suitability of various 
classes of rocks for road metal; more attention 
might with advantage be given in this country to 
the systematic testing of road materials. 
The ninth chapter is devoted to a detailed 
account of the sources, characteristics, and physi- 
cal and chemical properties of bituminous ma- 
terials; the highway engineer will find informa- 
tion in this chapter of great value to him when 
considering the question of the utilisation of bitu- 
minous materials in any proposed road reconstruc- 
tion work. The next three chapters explain fully 
how these bituminous materials are best employed 
for dust-preventive purposes on ordinary roads and 
in the construction of bituminous macadam pave- 
ments and bituminous concrete pavements; the 
mechanical plant required for these operations is 
described in detail. 
In the next five chapters the author treats of 
asphalt, wood-block, brick, and stone-block city 
roadways, describing the latest methods of con- 
structing each type of roadway and of the machin- 
ery and other appliances required for their econo- 
mical and speedy construction. 
NO. 2445, VOL. 98] 
[SEPTEMBER 7, 1916 
The remainder of the book is devoted to a brief 
but valuable discussion of the relative advantages 
and disadvantages of various types of roadway, 
and to an account'of the methods of constructing 
the side-walks, curbs, gutters, culverts, bridges, 
and other details of road construction. . 
The book is well illustrated’ and thoroughly up- 
to-date, and should prove a welcome addition to 
the reference library of every engineer engaged on 
roadway design, construction, and maintenance. 
T. Hie 
OUR BOOKSHELF. 
The Military Map: Elements of Modern Topo- 
graphy (French School of War). Pp. vii+130. 
(London: Macmillan and Co., Ltd., 1916.) 
Price 2s. 6d. net. 
In this book the authors set out to discuss the 
topographical map which has been produced 
especially for military purposes, and to treat par- 
ticularly of the French General Staff map on the 
scale of 1: 80,000. An introduction deals with 
the general principles on which a survey is carried 
sentation of detail and relief, and to some informa- 
tion relating to the French 1 : 80,000 map. 
It cannot be said that the result is satisfactory 
as an introduction to military topographical maps 
or as a description of the French map.. The 
authors do not seem to have that practical 
acquaintance with topographical surveying which 
would have enabled them to avoid several ‘mis- 
takes which occur, and render the book mislead- 
ing for a beginner. The statement in the intro- 
duction that in triangulation the actual angles of 
the plane triangle formed by three stations are 
measured could not have been made by anyone 
who had used a theodolite, and is quite misleading 
as describing an operation in which horizontal 
angles are determined. Map projections are not 
merits and demerits of those which are instanced 
might have been given, The retention of French 
terms is stated in the preface to be intentional, 
but it would have made the book much easier to 
read if after once quoting the French term the 
glossary of the French terms added as an appen- 
dix; as it is, many existing English terms do 
not appear, and some new ones are coined for 
which there is no need. 
The relief of the ground is attributed to certain 
portions of the soil having sunk while others have 
been lifted, but no suggestion of the modelling of 
the surface by erosion appears. In treating of 
relief, the theoretical principles of contours and 
hachures are given, but in practice these are not 
strictly followed, and the reasons for the modifi- 
cations should be given; the use of colour is not 
alluded to. Orientation in the field is the subject 
of the last chapter, but in advocating the use of 
the watch for this purpose, the error which may 
be introduced at different times and places should 
| have been carefully explained. H. Goa 
out, while five chapters are devoted to the repre-— 
satisfactorily treated, and at least the respective - 
English equivalent had been employed, and a 
