This is a translation of his final version of 1781, and is leaned to that of Kenneth Glyn Jones, published in his book, Messier's Nebulae and Star Clusters.
On June 20, 1764, in a good sky, M. Messier looked for this nebula without being able to discover it.
[Hev 380, 381, 382, 383; Der 2, 3, 4, 5] Hevelius, in the same work, reports the positions of four nebulae; one on the forehead of Capricorn, the second preceding the eye, the third following the second, and the fourth above them and attending the eye of Capricorn: M. de Maupertuis reported the positions of these four nebulae in his Discours sur la Figure des Astres, 2nd edition, page 109. M. Derham mentions them also in his Memoire printed in the Philosophical Transactions, No. 428, p. 70. One also finds these nebulae on many planispheres and celestial globes.
M. Messier looked for these four nebulae on July 27, August 3, and October 17 and 18, 1764, without being able to discover them, and he doubts they exist.
[Hev 618, 619; Der 6, 7] In the same work, Hevelius reports the positions of two other nebulae, one on the near side of the star which is above the tail of Cygnus, and the other on the far side of the same star.
On October 24 and 28, 1764, M. Messier looked carefully for these two nebulae without being able to find them. M. Messier clearly saw at the end of the tail of Cygnus, the star pi, a cluster of small stars [M39], but the position he determined was different from that which Hevelius reported in his work.
[Hev 1113; Der 11] Hevelius also reported in the same work the position of a nebula situated in the ear of Pegasus.
M. Messier looked for it in fine weather, in the night of October 24 and 25, 1764, without being able to find it, unless it is the same as the nebula which M. Messier has observed between the head of Pegasus and that of Equuleus. See No. 15 in his catalog.
[Lac I.11] M. l'Abbe de la Caille, in his Memoir on the nebulae of the southern pole, printed in the volume of the (Memoirs of the) Academy of 1755, p. 194, reports the position of a nebula which resembles, he said, the small nucleus of a comet; its Right Ascension as of Jan. 1, 1752, is 18d 13' 34" and its Declination S 33d 37' 5".
On July 27, 1764, in an entirely serene sky, M. Messier looked for this nebula
in vain: perhaps the instrument which M. Messier employed was not sufficient to
find it. It was later seen by M. Messier. See No. 69.
[This identification by Messier is probably a misidentification: Lac I.11 is probably an asterism of 3 stars, while globular cluster M69 is another object, an original Messier discovery - hf]
[Cassini, might be M50] M. de Cassini reported in his Elements of Astronomy, p. 79, that his father discovered a nebula in the area between Canis Major and Canis Minor and which was one of the finest to be seen in the telescope.
M. Messier looked several times for this nebula in a serene sky, without being able to find it, and he presumes it might have been a comet just becoming visible or disappearing, for nothing resembles a nebula more than a comet which is just becoming visible in an instrument.
[55 And] In the great Catalog of Stars by Flamsteed, there is reported a position of a nebula situated in the right leg of Andromeda, having R.A. 23d 44' (1h 34.9m) and polar distance 50d 49' 15" (Dec N 39d 10' 45").
M. Messier looked for it on October 21, 1780 with his achromatic telescope without being able to find it.
Last Modification: April 18, 2005