ayei 
NATURE 
[APRIL 4, 1907 
characteristics of railway motors, upon the design of 
which Mr. Hobart is an acknowledged authority. 
Throughout the whole of this section a liberal use 
is made of graphical methods, and a number of curves 
referring to the energy consumption under different 
conditions in actual practice is given. 
Chapter v. deals with the generating plant, and 
is, in our opinion, so far as the practical value of 
the information contained is concerned, scarcely so 
useful as the rest of the book; considerable space 
is devoted to descriptions of tramway generating 
stations, which, however up to date at the time of 
construction, are hardly representative of the most 
modern practice. The question of power-station 
design is a subject of its own, and is not one upon 
which the railway engineer, pure and simple, is 
often called upon to express an opinion. A design 
is given, however, of a proposed 10,000-kilowatt 
station, but, so far as can be judged from the draw- 
ing, the ‘‘complete unit’’ system by which, for 
safety reasons, the plant and buildings are entirely 
subdivided does not appear to be recommended. 
Interesting tables of the comparative cost and annual 
over-all efficiencies of various generating stations are 
given. 
A chapter upon the transmission of the electrical 
energy calls for no particular comment; sections of 
the cables adopted on various railway systems and 
the sizes of such cables are given. Particulars are 
also given of the cost of these cables, but the value 
of this is, of course, greatly dependent upon the price 
of copper. Substations are next dealt with, details 
being given of a very large number of actual sub- 
stations used in railway work. 
Chapter viii., dealing with the distributing system, 
in other words the third rail, is of more interest, and 
contains a number of tables dealing with recent prac- 
tice in this connection; overhead work is also illus- 
trated, though not so fully as could be wished. 
Part iii. deals with rolling-stock, and is replete 
with illustrations and working drawings of loco- 
motives and carriages. This portion of the book, 
however, shows signs of haste in editing, and in 
future editions we would suggest that the efficiency 
curves of motors which it contains, and, in fact, the 
reference to motors generally, should be gathered 
together in one section, namely, chapter iv., where 
most of them are already to be found, instead of 
being again dealt with under locomotives; certain 
of the data of rolling-stock given in chapter iv. would, 
in our opinion, be more easily found in the chapter 
which is specially devoted to that branch. 
These are, however, minor criticisms. The work 
is one of great practical value to all railway engineers, 
and will be further enhanced if in future editions more 
actual illustrations of the total costs of operation of 
electrified steam railways can be furnished. The 
North-Eastern Railway, the Lancashire and York- 
shire, and the District Railways have all been in 
operation long enough to furnish data of the greatest 
commercial value. 
The general ‘“‘ get up’ of the work is excellent, 
as are the reproductions of the various drawings. 
NO. 1953, VOL. 75] 
OUR BOOK SHELF. 
L’Année technique, 1906. By A. Da Cunha. Pp. 
xii+237; illustrated. (Paris: Gauthier-Villars, 
1906.) Price 3.50 francs. 
SINCE 1901 the author has.each year prepared in 
attractive form a concise summary of recent progress 
in engineering, and his series of volumes cannot fail 
to prove of inestimable value to the student of French 
industrial history. His annual summary is not a 
mere compilation of disconnected notes, but a collec- 
tion of essays written with originality, technical 
knowledge, and literary skill. . 
The subjects dealt with in the record for 1906 com- 
prise accidents in works, the heating and water- 
supply of houses, public works, and locomotion. A 
museum illustrating the prevention of accidents in 
works having recently been inaugurated at the Con- 
servatoire National des Arts et Métiers, Paris, the 
author has seized the opportunity of dealing at some 
length with the subject of industrial hygiene, and 
describes the museums that have been established 
with the object of bringing to public notice the 
arrangements that have been found by experience 
adapted for the protection of workmen in various 
industries. Museums of this kind exist at Zurich, 
Amsterdam, Vienna, Munich, Berlin, and Paris. The 
problem of efficaciously heating dwelling-houses is 
one that has long been under consideration. The 
old French fireplace, in which, it has been said, the 
hottest place is at the roof, has been superseded by 
modern fireplaces, by fixed or movable stoves, and 
by heating with steam or hot water. 
Many ingenious improvements are described by the 
author, who also gives some useful advice on this 
important topic. Other interesting subjects dealt 
with include the installation of the huge compressed- 
air caissons for the passage of the Paris Metropolitan 
Railway under the Seine, the recent developments in 
automobile transport, and locomotion on ice and 
snow. The numerous illustrations have been care- 
fully chosen and well executed, and the volume is pro- 
duced in an attractive style at a modest price. Mr. 
Alfred Picard contributes a preface, which, like the 
rest of the volume, may be studied with profit and 
pleasure, not only by the engineer, but also by the 
general reader desirous of acquainting himself with 
the events of the day. 
Liseases of Fruit and Fruit-bearing Plants. (Board 
of Agriculture and Fisheries.) Seven diagrams and 
text. (London: Printed for H.M. Stationery Office 
by Darling and Son.) 
Tue Board of Agriculture and Fisheries has issued 
a series of seven small coloured diagrams illustrative 
of a number of common diseases met with in culti- 
vated plants, especially those which are grown for 
the sake of their fruit. They are adapted for use in 
schools in the country districts. They illustrate the 
general appearance of the diseased fruits, without any 
botanical details. Indications are given as to the 
best methods of prevention. The use of Bordeaux 
mixture is frequently and judiciously recommended, 
but no instructions are given as to the way in which 
the mixture should be prepared. It is certain that, in 
spite of the publicity which has been given to this 
excellent fungicide, many cultivators do not yet know 
how to prepare it. The use of liver of sulphur is 
also recommended, but the caution is not added that 
it should not be allowed to come in contact with the 
paint on frame or greenhouse so as to prevent the 
discoloration that would otherwise ensue. 
No attempt is made to indicate the degree of injury 
inflicted by various fungi; thus the first of the series, 
the ‘‘strawberry leaf-spot,’’ is of very little conse- 
