its modern uses possible.--The universal wire.--Conductors and non conductors.--Electricity an exception in the ordinary Laws of Nature.--A dual nature: "Positive" and "Negative."--All modern uses come under the law of Induction.--Some of the laws of this induction.--Magnets and Magnetism.--Relationship between the two.--Magnetic "poles."--Practical explanation of the action of induction.--The Induction Coil.--Dynamic and Static Electricity.--The Electric Telegraph.--First attempts.--Morse, and his beginnings.--The first Telegraph Line.--Vail, and the invention of the dot-and-dash alphabet.--The old instruments and the new.--The final simplicity of the telegraph.

cables.--The story of the first cable.--Field and his final success.--The Telephone.--Early attempts.--Description of Bell's invention.--The Telautograph.--Early attempts and the idea upon which they were based.--Description of Gray's invention.--How a Telautograph may be made mechanically.

the conductor of a current.--The first Electric Light.--The Arc Light, and how constructed.--The Incandescent.--The Dynamo.--Date of the invention.--Successive steps.--Faraday the discoverer of its principle.--Pixü's machine.--Pacinatti.--Wilde.--Siemens' and Wheatstone.--The Motor.--How the Dynamo and Motor came to be coupled.--Review of first attempts.--Kidder's battery.--Page's machine.--Electric Railroads.--Electrolysis.--General facts.--Electrical Measurements.--"Death Current."--Instruments of Measurement.--Electricity as an Industry.--Medical Electricity.--Incomplete possibilities.--What the "Storage Battery" is.