( 3) 
Cooper—PRIMARY BATTERIES: THEIR CONSTRUCTION 
AND USE. By W.R. Cooper, M.A. Fully Illustrated. Price tes. 6d. nett. 
Author's Preface—Extract.—Primary Batteries form a subject from which much has been 
hoped, and but little realised. But even so, it cannot be said that the advance has been small; 
and consequently no apology is offered for the present volume, in which the somewhat scattered 
literature of the subject has been brought together. Recent years have seen important additions 
to the theory of the voltaic cell, and therefore a considerable number of pages have been devoted 
to this part of the subject, although it is impossible to do more than give a superficial sketch of 
the ,theory in a volume like the present. With regard to the practical part of the subject, this 
volume is not intended to be encyclopzedic in character; the object has been rather to describe 
those batteries which are in general use, or of particular theoretical interest. As far as possible, 
the Author has drawn on his personal experience, in giving practical results, which, it is hoped, 
will add to the usefulness of the book.. Owing to the importance of the subject, Standard Cells 
have been dealt with at some length. Those cells, however, which are no longer in general use 
are not described ; but recent work is summarised in some detail so as to give a fair idea of our 
knowledge up tothe present time. It has also been thought well to devote a chapter to Carbon- 
Consuming Cells. Very little has been written upon this subject, but it is of great interest, and 
possibly of great importance in the future. 
Curtis-Hayward—A DIGEST OF THE LAW OF ELECTRIC 
LIGHTING, ELECTRIC TRACTION AND OTHER SUBJECTS. By A.C. 
Curtis- Hayward, B.A., A.ILE.E. Price 3s. 6d., post free. Published annually in March. 
Being a full critical abstract of the Electric Lighting Acts, 1882 and 1889, of the Tramways 
Act, 1870, and of the documents issued from time to time by the Board of ‘lrade dealing with 
Electric Lighting, Electric Traction, &c., including the Rules as to the procedure in connection 
with applications to the Light Railway Commissioners for Orders under the Light Railways Act, 
1896, and forms of accounts for Board of Trade returns for Electricity Supply Undertakings. The 
Digest treats first of the manner in which persons desirous of supplying electricity must set to 
work, and then of their rights and obligations after obtaining Parliamentary powers ; and gives in 
a succinct form information of great value to Local Authorities, Electric Light Contractors, &c., 
up to date. The Board of Trade Regulations as to the Supply of Electrical Energy, the London 
County Council Regulations as to Overhead Wires, Theatre Lighting, &c., together with the Bye- 
laws enforced in pursuance of Part II. of the Public Health Acts Amendment Act, 1890, by the 
various Urban Sanitary Authorities are also given. 
Ewing—MAGNETIC INDUCTION IN IRON AND OTHER 
METALS. ‘By Prof. J. A. Ewing, M.A., B.Sc., F.R.S., Professor of Mechanism and 
Applied Mechanics in the University of Cambridge. 382 pages, 173 Illustrations. Price 
ros. 6d., nett. Third Edition. ‘ 
Synopsis of Contents.—After an introductory chapter, which attempts to explain the 
fundamental ideas and the terminology, an account is given of the methods which are usually 
employed to measure the magnetic quality of metals. Examples are then quoted, showing the 
results of such measurements for various specimens of iron, steel, nickel and cobalt. A chapter 
on Magnetic Hysteresis follows, and then the distinctive features of induction by very weak and 
by very strong magnetic forces are separately described, with further description of experimental 
methods, and with additional numerical results. The influence of Temperature and the influence 
of Stress are next discussed. The conception of the Magnetic Circuit is then explained, and 
some account is given of experiments which are best elucidated by making use of this essentially 
modern method of treatment. 
Fisher—THE POTENTIOMETER AND ITS ADJUNCTS. (A 
Universal System of Electrical Measurement.) By W. Clark Fisher. Price 6s., post 
free; eros, 6s. 6d, 
The extended use of the Potentiometer System of Electrical Measurement will, it is hoped, 
be sufficient excuse for the publication of this work, which, while dealing with the main instru- 
ment, its construction, use and capabilities, would necessarily be incomplete without similar 
treatment of the various apparatus which, as adjuncts, extend the range and usefulness of the 
whole system. 
‘he engineer or practical man demands that he shall be shown results quickly, plainly and 
accurately with a minimum of trouble, understanding, and consequently ‘Time,’ and on that 
account prefers—like all good mechanics—to have one good instrument, which, once understood 
and easily manipulated, can be used in a variety of ways to suit his needs. I[t is to this fact, 
undoubtedly, that the ‘‘ Potentiometer ” method of measurement owes its popularity. Its accuracy 
is rarely, if ever, impugned. Measurements made by it are universally accepted amongst engi- 
neers, and it might be well termed a “ universal ” instrument in “ universal” use. 
Fisher and Darby—STUDENTS’ GUIDE TO SUBMARINE 
CABLE TESTING. By H. K. C. Fisher and J. C. H. Darby, New and Enlarged 
Edition. Fully Illustrated. Price 7s. 6d. nett, post free; abroad 8s. , 
The Authors of this book have, for some years past, been engaged in the practical work of 
of Submarine Cable Testing in the Eastern Extension Telegraph Companys service, and 
have embodied their experience in a Guide for the use of those in the Telegraph Service 
who desire to qualify themselves for the examinations which the Cable Companies have recently 
instituted. To those desirous of entering the Cable Service, Messrs. Fisher and Darby’s book is 
indispensable, as it is now necessary for probationers to pass these examinations as part of the 
qualification for service. i i. 
A valuable set of Questions and Answers is added to the New and Enlarged Edition. 
“THE ELECTRICIAN ” PRINTING & PUBLISHING CO., LTD., 
1, 2 and 3, Salisbury Court, Fleet Street, London, E.C, 
