30 Off A RLES O RIFFIN & GO. 'S P UBLICA TIONS. 



In Large Crown 8vo. Cloth. Pp. i-xvi-j-208. With 222 Illustrations. 



net. 



TELEGRAPHIC SYSTEMS, 



AND OTHER NOTES. 



A Handbook of the Principles on which Telegraphic Practice is Based. 

 BY ARTHUR CROTCH, of the Engineer-in-Chief's Department, G.P.O. 



CONTENTS. Batteries, Primary and Secondary. Universal Battery Working. 

 Duplex Telegraphy. Duplex and Quadruples Telegraphy. Automatic Telegraphy. 

 Multiplex Telegraphy. The Hughes Type Printing Instrument. The Baudot System. 

 The Murray Type Printing Telegraph. Test and Battery Boxes. Circuit Concentration, 

 <fec. Repeaters. Submarine Telegraphy. Wireless Telegraphy. INDEX. LIST OF 

 DIAGRAMS OP CONNECTIONS. 



^" This book is a particularly good one . . . we can thoroughly recommend it . . . 

 a handy book of ready reference." Electrical Reri, /-. 



"The treatise will In- of much lu'lp to the telegraph engineer, and to the student 

 in liis preparatory training and it can be thoroughly recommended.' 1 Electrician. 



NINETEENTH EDITION. Leather, Pocket Size, with 810 pages. 8s. 6d. 



A POCKET-BOOK OF 



ELECTRICAL RULES & TABLES 



FOR THE USE OF ELECTRICIANS AND ENGINEERS. 



BY JOHN MUNRO, C.E., & PROF. JAMIESON, M.lNST.C.E., F.R.S.B. 



" WONDERFULLY PKRFKCT. . . . Worthy of the highest commendation we can 

 jive it." Electrician. 



GrRIFFIN'S ELECTRICAL PRICE-BOOK: For Electrical, Civil, 

 Marine, and Borough Engineers, Local Authorities, Architects, Railway 

 Contractors, &c. Edited by H. J. DOWSING. SECOND EDITION. 8s. 6d. 



ELECTRIC SMELTING AND REFINING. [See p. 52. 



ELECTRO-METALLURGY, A Treatise on. [See p. .vj. 



ELECTRICAL PRACTICE IN COLLIERIES. [See p. 4_>. 



ELECTRICAL SIGNALLING IN MINES. [See p. 43. 



In Large Crown 8vo. Handsome Cloth. 15s. net. 



ELECTRICAL THEORY 



AM> Tin; 



PROBLEM OF THE UNIVERSE, 



IIv <;. W. DE TUNZELMANN, B.Sc., LONDON, 



Member of UK- Institute of Electrical Engineers ; formerly Professor of Natural 



Philosophy and Astronomy, II. M.S. " Britannia," Dartmouth. 



CONTENTS. Fundamental Electrical Phenomena. Units and Measurement. 

 M. -ailing and Possibility of a Mechanical Theory of Electricity. The Ether. The Ktl-.-r 

 M ;i r'ram.-uork of K.-tVrene,- for Motion. -The Relations between Ether and Moving 

 Matter. Electric Conduction in Gases. The Faraday-Maxwell Theory.- The Electron 

 Theory. Magnetism ami tin- Dissipation of Energy. Contract Electritieation and 

 Electrolysis. Metallic Conduction, optical Phenomena. -The Mechanism of Radiation. 

 General Phenomena of Radio Activity. Transmutations of Radio-Active Substances. 

 Ages of the Sun and Earth. The Solar ('arona. The Aurora, and Comets' Tails. 

 R-idio-Aetivity in Stars and Nebula-. Arrangement and Number of Atoms in a Mole- 

 cule. Changes in the Aspect of Fundamental Mechanical Principals. Gravitation 

 and Cohesion. The Place of Mind in the Universe. Mathematical and other Appen- 

 d ices. INDEX. 



LONDON: CHARLES GRIFFIN & GO,, LIMITED, EXETER STREET, STRAND. 



