Page:Popular Science Monthly Volume 8.djvu/293

Rh During the last summer M. Trouvelot was invited by the superintendent of the United States Naval Observatory to visit Washington for the purpose of making drawings of nebulæ, etc., by means of the twenty-six inch Clark refractor. By the courtesy of Admiral Davis



I am able to give a drawing of the Horseshoe Nebula as delineated by M. Trouvelot from observations made jointly by him and by myself. Pretty much the same method was adopted in this drawing as in Fig. 6, but the vastly more complex structure of the nebula itself is what might have been expected from an increase of eighteen times in the light, over M. Trouvelot's six-inch telescope.