Astronomnteat and Nautical Collections. 89 
No. Year. 
2 297, 1753, p. 58. Mém. Par. 1730, p. 284. The hyperbolic 
and parabolic orbits of Burckhardt. Conn. des tems, 182]. 
51. 1737, Computed from Bradley's own observations, extending from 
26 Feb. to 2 April. Phil. Trans. N. 446, p. 111. Pingré II. 
p- 45. Struyck, 1740, p. 301. 
52, 1737, The observations made at Pekin were published in the Mon. 
Corr. XXL. p. 316. Conn! des tems. 1812, p. 409. 
53. 1739. The observations are by Zanotti, from the 28th May to the 18th 
August. N. Acta Erudit. 1740, p- 166. Comm. Inst. Bon. II. 
p. ili, p. 73. Struyck, 1753, p. 64. The second orbit, by.Za- 
notti, is only a first approximation, still remaining imperfect. 
94. 1742. For the numerous observations of this comet see Pingré II. 47. 
59. 1743, In part. very imperfectly observed. The observations are 
j principally collected in Struyck, 1753, p. 75. 
56. 1743. Observed imperfectly, and by Klinkenberg alone, from 18 Aug. 
oa to 13 Sept. Struyck, 1753, p. 76,77. The observations, 
which are also inserted by Pingré I, p- 52, differ sometimes 
1° and more from the elements assigned. 
57. 1744. Besides the observers and computers of this celebrated comet 
quoted by Pingré, IT. p. 52, and Struyck, p. 78, some valuable 
matter may be found in Chéseaux Traité dela Cométe, Laus. 
1744, and Hiorter Trans. Swed. Acad. of Sciences. 
_58. 1747. Discovered by Chéseaux the 13th Aug. 1746, and last ob- 
served by Maraldi the 5th Dec. 1746. The orbits of Ma- 
raldi and Lacaille are the best. Pingré II. p. 57. Struyck, 
1753. p. 92. 
59. 1748. Especially observed by Maraldi, Mém. Par, 1748, p. 229. 
60. 1748, Observed only three ‘times imperfectly by Klinkenberg, the 
19th, 20th, and 22d May. Struyck, 1753, p- 96. Bessel has 
reduced the observations with greater care. Berl. Astr. Jahrb. 
1809, p. 99. The imperfect elements, time of the Perihe- 
lium, 1748, 22d April Q 9°, 24°, Inclination 76°, Least 
distance 0.5, Motion retrograde, which Delambre as- 
cribes to Burckhardt, and respecting which I can find no 
further information, cannot possibly belong to either of the 
computed comets of this year: so that they must have been 
derived from the alleyed observations of the silly Kinderman, 
which deserve no credit whatever. 
61. 1757, Bradley's observations and elements are preferable to the rest. 
Phil. tr. L. Part. i. p. 408. The other observations may be 
found collected by Pingré, Mém. Par. 1757, p- 97. 
62. 1758, Messier observed the comet from the 15th Aug. to the 2d Noy. 
_Mém, Par, 1759, p. 154, 1760, p. 165, 463. 
(15).1759. Celebrated and predicted re-appearance of Halley's comet. 
Pingré IL. p. 63, gives references to works in which the ob- 
servations and the elements may be found. Burckhardt's 
___ orbit, preferable to all the rest. ‘Conn. des tems, 1819. 
63, 1759. Pingré prefers his own elements. The comet was observed 
from the 25th June to the 16th March 1760. Pingré I. 
5 p- 68. 
64. 1759. Observed from the 8th Jan. to the Sth Feb. 1760, Pingré II, 
p- 70. ; 
65. 1762, Discovered by Klinkenberg the 17th May, observed to the 2d 
July. The refraction had been neglected in the reduction of 
