1. For Bertrand’s review, see below. Schjellerup 1882 was motivated by Schorr’s book to communicate the observation data from the Copenhagen Observatory.
2. William Herschel, the German-Danish astronomer Heinrich Louis d'Arrest (1822-1875) and a few other astronomers had searched in vain for a moon around Mars. According to d'Arrest, there was little hope of seeing a Mars satellite, should it exist (d'Arrest 1865). On the discovery, see Gingerich 1970 and Dick 1988. Earlier in the century four more moons were discovered: the moon around Neptune (William Lassell, 1846), one more Saturn moon (George P. Bond, 1848) and two more Uranus moons (William Lassell, 1851). On Hall's discovery and its reception, see also Hall 1878 and Nature
3. 16 (1877), pp. 397-398, 427-428.
4. Bertrand 1882, p. 203. Similarly in Bertrand 1875, p. 458.
5. Bertrand 1875.