Page:Sir William Herschel, his life and works (1881).djvu/150

128 is increased, so the boundaries of the visible universe are widened, and the number of stars increased to millions and millions. Whoever has followed the history of the series of telescopes will have observed this. But was not content with the bare fact, but strove ever to know how far a telescope of a certain construction and size could penetrate, compared with the naked and unassisted eye. These investigations were never for the discovery of new facts concerning the working of his instruments; it was for the knowledge of the distribution of the fixed stars in space itself that he strove.... instruments were designed to aid vision to the last extent. They were only secondarily for the taking of measures. His efforts were not for a knowledge of the motions, but of the constitution and construction of the heavenly bodies."

Besides the stands for his telescopes, which were both ingenious and convenient, devised many forms of apparatus for facilitating the art of observation. His micrometers for measuring position angles, his lamp micrometer, the method of limiting apertures, and the methods he used for viewing the sun may be mentioned among these.

Points in practical astronomy are considered all through the years of observation.