Page:Popular Astronomy - Airy - 1881.djvu/73

Crown, was Professor in one of the French Colleges. He gave lectures on the History of Civilization, and he maintained that France had been the great pioneer in science; that civilization generally had originated in France. I believe that in matters of science it is as stated by Guizot. When the question of the figure of the earth came to be debated, two celebrated expeditions were made under the auspices of the French government; the first great scientific expeditions ever made in the history of the world. The party composing one expedition was sent to Lapland, to make a triangulation in the way I have described, and to make corresponding observations with the Zenith Sector, beginning at Tornea, at the head of the Gulf of Bothnia, and carrying the survey northward for about fifty miles. Another party was sent to Peru to make a similar measurement, but about two hundred miles in length. And no two expeditions ever rendered themselves more justly celebrated than these. Now, observe the results.
Fig. 21.In Figure 21, AB represents the Lapland measure, a b the Peruvian measure. It was found, that in Lapland they had to go 69¾ miles, or something like that, in order that the directions of the verticals should change one degree. It was found in Peru that they had to go only 69 miles, in order that the direction should change one degree. From this, it follows that the verticals AH and BH in Lapland meet at a point H, whose distance from A or B is about 4000 miles; and that the verticals a h and b h in Peru meet at a point