His scientific labors having been finished, La Condamine conceived the idea of returning home by way of the Amazon River; though difficulties attended the project, which we who live in a land of mighty rivers, traversed by steamboats, can hardly imagine. The only means of navigating the upper waters of the river was by rafts or canoes; the latter capable of containing but one or two persons, besides a crew of seven or eight boatmen. The only persons who were in the habit of passing up and down the river were the Jesuit missionaries, who made their periodical visits to their stations along its banks. A young Spanish gentleman, Don Pedro Maldonado, who at first eagerly caught at the idea of accompanying the French philosopher on his homeward route by way of the river, was almost discouraged by the dissuasives urged by his family and friends, and seemed inclined to withdraw from the enterprise; so dangerous was the untried route esteemed. It was, however, at length resolved that they should hazard the adventure; and a place of rendezvous was appointed at a village on the river. On the 4th of July, 1743, La Condamine commenced his descent of one of the streams which flow into the great river of the Amazons. The stream was too precipitous in its descent to be navigated by boats of any kind, and the only method used was by rafts. These are made of a light kind of wood, or rather cane, similar to the bamboo, the single pieces of which are fastened together by rushes, in such a manner, that they yield to every shock of moderate violence, and consequently are not subject to be separated even by the strongest. On such a conveyance, the French philosopher glided down the stream of the Chuchunga, occasionally stopping on its banks for a day or two at a time to allow the waters to abate, and admit of passing a dangerous rapid more safely; and sometimes getting fast on the shallows, and requiring to be drawn off by ropes by the Indian boatmen. It was not till the 19th of July that he entered the main river at Laguna, where he found his friend Maldonado, who had been waiting for him some weeks. On the 23d of July, 1743, they embarked in two canoes of forty-two and forty-four feet long, each formed out of one single trunk of a tree, and each provided with a crew of eight rowers. They continued their course night and day, in hopes to reach, before their departure, the brigantines of the missionaries, in which they used to send once a year, to Pará, the cacao which they collected in their missions, and for which they got, in return, supplies of European articles of necessity.