Hevelius, in his Prodronie Astronomie, gives the position of a nebula located at the very top of the head of Hercules at right ascension 252°24’3”, and northern declination 13°18’37”.

On 20 June 1764, under good skies, M. Messier searched for this nebula, but was unable to find it.

In the same work, Hevelius gives the positions of four nebulae, one in the forehead of Capricornus, the second preceding the eye, the third following the second, and the fourth above the latter and reaching the eye of Capricornus. M. de Maupertuis gave the position of these four nebulae in his work Figure of the Stars, second edition, page 109. M. Derham also mentions them in his paper published in Philosophical Transactions, no. 428, page 70. These nebulae are also found on several planispheres and celestial globes.

M. Messier searched for these four nebulae, namely on 27 July and 3 August, and 17 and 18 October 1764, without being able to find them, and he doubts that they exist.

In the same work, Hevelius gives the position of two other nebulae, one this side of the star that is above the tail of Cygnus, and the other beyond the same star.

On 24 and 28 October 1764, M. Messier carefully searched for these two nebulae, without being able to find them. M. Messier did indeed observe, at the tip of the tail of Cygnus, near the star π, a cluster of faint stars, but its position was different from the one reported by Hevelius in his work.