At his own expense, the best scientific instruments were procured, and June 5, 1799, at two o'clock in the afternoon, he and Bonpland, with their crew and a few others, sailed away, in the corvette Pizarro, for a five years' journey. He sent tender farewell messages back to "his family," as he called William's children, and then stifled any feelings of loneliness or homesickness which he had in his heart, by his favorite motto, "Man must ever strive after all that is good and great." June 20, they were at the foot of the Peak of Teneriffe. He wrote to his brother: "I am quite in a state of ecstasy at finding myself at length on African soil, surrounded by cocoa-nut palms and bananas.... I returned last night from an excursion up the peak. What an amazing scene! What a gratification! We descended some way into the crater, perhaps farther than any previous scientific traveller.... What a remarkable spectacle was presented to us at this height of eleven thousand five hundred feet.... At two in the morning we were already on our way towards the last cone. The heavens were bright with stars, and the moon shone with a gentle radiance; but this calm was soon to be disturbed. The storm raged violently round the summit; we were obliged to cling fast to the edge of the crater. The wind rushed through the rifts with a noise like thunder, while a veil of cloud separated us from the world below." After a voyage of nineteen days, the ship entered the harbor of Cumana, on the north coast of South America. Here they enjoyed the new and strange scenes; the houses built of satin-wood; the copper-colored Indians outside the town, living in bamboo huts, covered with the leaves of the cocoa-nut palm; these great trees from fifty to sixty feet high, with large red bunches of flowers. "Even the crabs," said Humboldt, "are sky-blue and gold!" By November they had dried more than sixteen hundred plants, and described about six hundred new varieties. He had taken observations of the solar eclipse of October 28, and so severely burnt his face that he was obliged to remain in bed for two days. Going to Caracas, they spent two months and a half climbing mountains, visiting hot springs, and forming an intimate acquaintance with tigers, crocodiles, monkeys, and boa constrictors. Here they discovered the singular cow-tree, with dry and tough leaves, but which gives out a sweet nourishing milk when an incision is made in its stem. "At sunrise this vegetable spring is the richest: then the negroes and the natives come from all sides, provided with large vessels to collect the milk, which turns yellow and thickens on the surface."