Orbituary: AN 268, 195 (1939)

Wirtz and Kobold continued Winnecke’s observations of nebulae with the 18" Merz refractor at Straßburg Observatory. In 1911 Wirtz published the Straßburg observations as Generalkatalog der am großen Refraktor in Straßburg beobachteten Nebelflecke 1881–1910. The catalogue contains the positions of 1257 objects for the epoch 1900, among them all of those discovered with the great refractor. Wirtz compared the results with other works, listing corrections too.