Riggenbach, Albert, *#*#E.200a.57 Beobachtungen uber die Dammerung insbesondere uber das Purpurlicht und seine Beziehungen zum Bishop'schen Sonnenring. Habilitationsschrift,. Basel. H. Georg. 1886. 105 pp. 89. "Bishop's ring" is named after Sereno E. Bishop and is an atmospheric or meteorological phenom- enon, first observed after. the eruption, on Aug. 26, 1883, of the volcano Krakatoa, in Java. The appearnace is a solar halo and is connected with (Continued. )