NOVEMBER 15, 1906| 
NATURE 
On 
iss) 
(4) The great increase in the utilisation of water- 
power in all parts of the world, mainly in connection 
with the electric transmission of energy, has led to 
much more attention being devoted to this branch 
of engineering in all technical colleges, and this has 
naturally brought about a demand for text-books 
thoroughly up to date, and suited to modern develop- 
ments of the industry. Prof. Church has attempted 
both to supply this need on the part of engineering 
students, and at the same time to write a book which |, 
will be of service to practising engineers; the subject 
has been treated by him, therefore, both from the | 
theoretical and from the practical standpoint. 
After dealing with the general considerations which 
govern the design of all types of hydraulic motors, 
one chapter is devoted to the various forms of gravity 
motors—overshot, breast, and undershot wheels— 
which have been so largely displaced in modern days 
by the turbine. Before dealing with turbine design 
the author shows that there are three theorems which | 
lie at the basis of the theory of turbines and centri- | 
fugal pumps; these theorems are, in fact, funda- 
mental principles of mechanics, though the third pre- 
supposes the existence of “‘ steady flow ’’; this third 
theorem may be expressed as follows :— 
“Power of a turbine in steady motion=angular 
velocity x change of angular momentum experienced 
by the mass of water flowing per unit of time in its 
passage through the turbine.’’ 
These theorems are illustrated by a_ series of 
numerical examples worked out in full. 
In chapter iv. impulse wheels are considered, and 
the Pelton and the Girard impulse wheels are taken 
as illustrations of this type; in the next chapter the 
turbine proper, or ‘‘ reaction turbine,’’ is taken up, 
and as a preliminary to the discussion of the modern 
turbine the theory of the Barker’s mill is deduced; 
it is then shown that the Fourneyron turbine is a 
direct descendant of this old and simple form, and the 
theory of the Fourneyron form is then worked out 
both when friction is disregarded and when it is 
taken into account. Prof. Church then classifies 
turbines under four heads—(1) radial outward-flow, 
(2) radial inward-flow, (3) axial flow, (4) mixed flow— 
and deals with each of these classes in detail; he 
gives descriptions, with excellent illustrations, of 
well-known makes of each type, and concludes the 
chapter with the general theory of reaction turbines. 
The testing and regulating of turbines form the sub- 
ject-matter of chapter vi., and a description is given 
of the Holyoke testing fume. The following chapter 
is devoted to the theory and construction of centri- 
fugal pumps, and the formulz deduced are illustrated 
by working out in full numerical examples. 
The flow of water over weirs and through pipes 
and open channels is treated mainly from the point 
of view of the designer of turbine machinery, and in 
connection with this portion of the book there is a 
series of useful diagrams in the appendix for Kutter’s 
coefficient, &c. 
The book concludes with a chapter on pressure 
NO. 1933, VOL. 75] 
engines, and accumulators, the 
Worthington water-motor pump and the Brotherhood 
pressure being taken as examples. Prof. 
Church’s book will undoubtedly be a recognised text- 
book for advanced engineering students. 
(5) This book, originally intended to give a popular 
account of the history, construction, and operation 
hydraulic rams 
engine 
both of water and steam turbines, has been extended 
in its and the dealt with the 
important problem of blade design in such a way as 
to make it a text-book useful the technical 
student. After giving a brief history of the evolution 
of the water turbine, the conditions which must be 
fulfilled if such machines are to be efficient are fully 
discussed; then follow several chapters in which recent 
modern types of both impulse and reaction turbines 
are described with the help of a series of good illus- 
trations; finally, this half of the book concludes with 
some details of the best methods of erecting water 
turbines and controlling them by governors. 
In part ii. the steam turbine is taken up, and 
naturally attention is chiefly devoted to the Parsons, 
De Laval, and Curtis turbines, as these are practically 
the three types which have so far been commercially 
successful; a full description is given of the prin- 
ciples underlying the design, and of the methods 
adopted in manufacturing the various parts of each 
of these well-known engines, and it is to be hoped 
that a study of this part of the book may do some- 
thing to dissipate the extraordinary ignorance and 
misconception which prevail among men, even of fair 
mechanical knowledge, in regard to the steam turbine 
and its possibilities. Special chapters are devoted to 
the application of the turbine to marine purposes, and 
a clear account is given of the rapid development in 
this field of work during the last few years both in 
the Royal Navy and in the merchant service. Turbo- 
blowers and rotary pumps are discussed in another 
chapter, and the advantages of these pumps over 
reciprocating pumps, where vast volumes of air have 
to be supplied, as is the case in connection with the 
blast-furnace industry, are clearly set forth. 
A series of appendices dealing briefly with the 
mathematical and mechanical principles involved in 
elementary engineering, with fluid motion, and with 
the behaviour of gas, conclude a book which will do 
much, it is probable, to make the layman take a more 
intelligent interest in this the latest and most striking 
development of the skill of the mechanical engineer. 
(6) This is an authorised translation of a book by 
Herr Dietrich, in which he describes the various 
patents for steam turbines and their accessories talen 
out by Mr. R. Schulz, engine-works manager of 
the Germania Shipyard at Kiel, and also the results 
of tests of the Schulz turbine, both when used for 
marine work and for the generation of electrical 
energy. 
The rest of the book is devoted to ex parte state- 
ments in reference to the controversy between Mr. 
Parsons and Mr. Schulz in regard to their respective 
inventions, which was eventually fought out in the 
Law Courts in an action brought for infringement of 
scope, author has 
also to 
