No one foresaw the result of these addresses. The course was so successful that it extended itself into sixty-one lectures, and covered a period of more than ten years' time. No admittance was charged, free tickets being given out to applicants. Very soon after the first lecture, a traffic sprang up in these free tickets, carried on by our Semitic friends, and the tickets soared to as high as three dollars each. Then the strong hand of the Government stepped in: the tickets were canceled, and the public was admitted to the lectures without ceremony. Boxes, however, were set apart for royalty and foreign visitors, some of whom came from England, Belgium, Switzerland and France. The size of these audiences was limited simply by the capacity of the auditorium, the attendance at first being about a thousand; later, a larger hall was secured and the attendance ran as high as four thousand persons at each address. The subjects were as follows: three lectures on the History of Science; two on reasons why we should study Science; four on the Crust of the Earth, and the nature of Volcanoes and Earthquakes; two on the form of Earth's Surface and the elevation of the Continents; five on Physical Geography; five on the nature of Heat and Magnetism; sixteen on Astronomy; two on Mountains and how they are formed; three on the Nature of the Sea; three on the Distribution of Matter; ten on the Atmosphere as an Elastic Fluid; three on the Geography of Animals; three on Races of Men. Every good thing begins as something else, and what was intended for the common people became scientific lectures for educated people. "The man who was most benefited by these lectures was myself," said Humboldt. Men grow by doing things. Lectures are for the lecturer. Humboldt found out more things in giving these lectures than he knew before--he discovered himself. And long before they were completed he knew that his best work was embodied right here--in doing for others he had done for himself. In attempting to reveal the Universe or "Cosmos," he revealed most of his own comprehensive intelligence. That many of his conclusions have since been abandoned by the scientific world does not prove such ideas valueless--they helped and are helping men to find the truth. These sixty-one "popular" and free lectures make up that stupendous work now known to us as "Humboldt's Cosmos." * * * * * Says Robert Ingersoll in his tribute to Alexander von Humboldt: "His life was pure, his aims were lofty, his learning varied and profound, and his achievements vast.