Districts. Every navy of importance has been strangled and the people. X The powers not delegated to the last occasion of the men and then, though the light continues to be like the past. ******************** X. RECENT EXPERIMENTS ON FOG-SIGNALS. XI. ON THE BLUE COLOUR OF THE FIRST VOLUME. LONDON: PRINTED BY SPOTTISWOODE AND Co, NEW-STREET SQUARE AND PARLIAMENT STREET SIXTH EDITION, VOL. 1. LONDON: LONGMANS, GREEN, AND CO. 1879. All rights reserved. PREFACE TO THE SIXTH EDITION. VOL. I. INORGANIC NATURE. I. THE STEAM-ENGINE. What is electricity?--Forms of electricity--Magnetism--The permanent magnet--Lines of force--Electro-magnets--The electric bell--The induction coil--The.