Growth of the art of printing--Birth of Richard M. Hoe--Sketch of the career of Robert Hoe--He comes to America--His marriage--Founds the house of "Robert Hoe & Co."--The first steam printing presses--He retires from business--Richard M. Hoe is brought up in the business--The mechanical genius of the house--The new firm--Richard Hoe's first invention--Obtains a patent for it--Visits England--Invents the double-cylinder press--Demand for increased facilities for printing--Mr. Hoe's experiments with his press--His failures--How the "Lightning Press" was invented--A good night's work--Patents his invention--The first "Lightning Press"--Demand for it--Rapid growth of the business of the firm--Statement of the operations of the house--Personal characteristics of Richard M. Hoe--The "Lightning Press" at work. CHAPTER XIX. SAMUEL COLT. Birth and parentage--A restless boy--Dislikes school--Early fondness for mechanical inventions--Is sent to boarding-school--Runs away to sea--The story of a boy's invention, and what came of it--Origin of the revolver--Returns home--His chemical studies--Dr. Coult--The lecturing tour--His success--Completes his design for the revolver--Patents his invention--Visits England--Discovery at the Tower of London--Returns home--Formation of the "Patent Arms Company"--Objections of the officers of the army and navy to the revolver--The Florida War--It is decided by the revolver--Triumph of Col. Colt--Cessation of the demand for arms--Failure of the company--Beginning of the Mexican War--Action of General Taylor--No revolvers to be had--A strange dilemma for an inventor--The new model--Contracts with the Government--Success of the revolver in Mexico--The demand from the frontier--Emigration to California and Australia--Permanent establishment of Col. Colt's business--The improved weapon--Builds a new armory--Description of his works at Hartford--A liberal employer--Other inventions of Col. Colt--His submarine telegraph--His fortune--His marriage--Visits to Europe--Attentions from European dignitaries--Witnesses the coronation of the Emperor of Russia--His last illness and death. CHAPTER XX. SAMUEL F.B. MORSE.