AbstractGet full access to this articleView all access options for this article.Get accessReferences1. Schaffer Simon , “Halley, Delisle, and the making of the comet”, in Thrower Norman J. W. (ed.), Standing on the shoulders of giants (Berkeley, 1990), 254–98.2. Gingerich Owen , “The missing Messier objects”, Sky and telescope, xx (1960), 196–9.