Astronomy, therefore, and navigation, both sciences the results of long ages of patient inquiry, have opened a communication between the uttermost ends of the earth; and therefore have had a slow, but certain effect upon the production of wealth, and the consequent diffusion of all the necessaries, comforts, and conveniences of civilized life. The connexion between manufactures and science, practical commerce and abstract speculation, is so intimate that it might be traced in a thousand striking instances. Columbus, the discoverer of America, satisfied his mind that the earth was round; and when he had got this abstract idea firmly in his head, he next became satisfied that he should find a new continent by sailing in a westerly course. The abstract notion which filled the mind of Columbus that the earth was a sphere, ultimately changed the condition of every living being in the Old World that then existed, or has since existed. In the year 1488, the first geographical maps and charts that had been seen in England were brought hither by the brother of Christopher Columbus. If these maps had not been constructed by the unceasing labours of men in their closets, Columbus would never have thought of discovering "the unknown land" which occupied his whole soul. If the scanty knowledge of geography which existed in the time of Columbus had not received immense additions from the subsequent labours of other students of geography, England would not have twenty-seven thousand merchant ships ready to trade wherever men have anything to exchange,--that is, wherever men are enabled to give of their abundance for our abundance, each being immensely benefited by the intercourse. A map now appears a common thing, but it is impossible to overrate the extent of the accumulated observations that go to make up a map. An almanac seems a common thing, but it is impossible to overrate the prodigious accumulations of science that go to make up an almanac. With these accumulations, it is now no very difficult matter to construct a map or an almanac. But if society could be deprived of the accumulations, and we had to re-create and remodel everything for the formation of our map and our almanac, it would perhaps require many centuries before these accumulations could be built up again; and all the arts of life would go backward, for want of the guidance of the principles of which the map and the almanac are the interpreters for popular use. [Illustration: Linnæus in his Lapland dress.]