Note 38 — William Herschel. (continued 3)

These have never been re-observed. They should be sought for with a powerful refractor, taking special precautions against the illumination of the field of view from neighboring bright stars. Herschel's reflectors were specially open to illusions produced in this way. His observations probably will remain untested until some large telescope is used in the way he adopted, i. e., in sweeping.