Perry’s visit to Europe was exceedingly well-timed to secure the largest results, for a revolution in optical science and applied methods of illumination, as well as in ships and guns, was at hand. Science and invention were to do much for the saving of human life as well as for its destruction. The balances of Providence were to settle to a new equilibrium. Crossing the channel, he visited Cherbourg and Brest, there finding the same courtesy and cordial reply to his questions. In Paris he came in contact with a number of distinguished scientific men. He was especially well assisted by the United States Agent, Mr. Eugene A. Vail. The illustrious Augustin Fresnel who had said in a letter to a friend, December 14, 1814, that he did not know what the phrase “the polarization of light meant,” was in 1819 crowned by the French Academy of Science as the first authority in optics. He had demonstrated to his countrymen the error of the old theory of the transmission of light by the emission of material particles. This he had achieved by the study of polarization. The practical application of his researches to the apparatus of lighthouses struck a death-blow to the old system of coast illumination. Among other pleasant experiences in the French capital, was a second visit to King Louis Philippe. Invited by His Majesty to an informal supper, at which the royal family were present, Captain Perry took his seat at their table as a guest feeling more honored by this private confidence than if at a state dinner. At the table sat the King’s wife and children, tea being poured by the Queen herself. At this time, the Duc d’Orleans, son of the King, was rejoicing over the recent birth of a son. His name was Louis Albert Philippe d’Orleans, Comte de Paris. He afterwards served in the Union armies during our civil war of 1861–65, and is the accomplished author of the best general history of that series of events yet published, _Historie de la Guerre Civile en Amérique_. At this time, November 1838, the infant boy was not quite three months old, and the talk and thoughts of the royal family were centered on him. Leaving Portsmouth December 10, by sailing packet, Perry arrived in New York, January 14, 1839. After a few days spent at home he went to Washington to deliver up his rich spoil of contemporaneous science, and his own elaborate reports, criticisms, and suggestions. His face was flushed with the irresistible enthusiasm of new ideas. And his thought was in the direction of the future. The wires of a magnetic telegraph had been strung across the campus of Princeton college, four years before this, by Professor Joseph Henry. Out of the discoveries of Faraday and Henry, brilliant results had sprung, of which application to the arts of war and peace was already being made. Both as a naval officer and as a lover of science, Perry rejoiced to see