FIG. 296.--Diagram repre-senting stellar aberration. Summary: C A B FIG. 296.-- Diagram repre- senting stellar aberration. From "Text Book of General Physics," by Joseph Sweetman Ames (1904) page 568 Method of Bradley.Another method by which the velocity of light could be determined was discovered by Bradley, the great English astronomer, in 1727. He had observed that if a fixed star was observed through a telescope, this instrument had to be pointed in slightly different directions at different times of the year; so that, if the image of the star were kept on the cross hairs of the telescope during the whole year, the instrument had to be kept in continual motion in such a manner that its end described a small curve. The explanation given by Bradley was extremely simple. Consider a long tube closed at its two ends by caps in which there are two openings directly opposite each other. A particle entering at one opening, with a motion parallel to the axis of the tube, will escape through the opening at the other end, if the tube is at rest. But, if the tube is moving at right angles to its length, the opening in Collections: Physics