86 Astronomical and Nautical Collections. 
No. Year. 
though the elements have some resemblance with those of the 
comets of 1683 and 1739, yet Burckhardt found that neither 
of these two orbits would accord with the observations of 565. 
Mon. Corr. X. p. 162, 
4. 837. Chinese observations. Pingré Com. I. p. 340. 
5. 989. Chinese observations, A very uncertain orbit. Mon. Corr. X. 
p- 167. 
6. 1066. Very uncertain orbit. Pingré I. p. 373. 
7. 1097. From Chinese observations of the 6th, 16th, and 17th October. 
Say. Etr. L p. 290. Mon. Corr. If. p. 417, XVI. p. 501. 
8. 1231. Chinese observations. Pingré I. p. 401. 
9. 1264. Phil. tr. XLVII. p. 281. Pingré I. p. 406. Mém. Par: 
1760. p. 195. Struyck Vervolg Amst. 1753. p. 108, 109. 
The identity with the comet of 1556 is uncertain from the 
want of precision in both orbits. 
10. 1299. Two European observations, and one Chinese: a third Euro- 
pean record does not agree. Pingré I. p. 418. 
11. 1301, Pingré has applied a correction to the European, and Burck- 
hardt to the Chinese observations, which could not otherwise 
be reconciled. Hence the diversity. Pingré I. p. 420, Mon. 
Corr. X. p. 164. 
12. 1337, Pingré I. p. 432. The orbit of Pingré is preferable to that of 
Halley, since it represents both the European and the Chi- 
nese observations tolerably well, while Halley's differs as far 
as 208 fromthe latter. 
13, 1351. Even the few elements, which Burckhardt has been able to 
assign, are very uncertain. Pingré I. p. 487. Mon. Cor. IIL. 
p- 415. Mem. Say. Etr. I. p. 290. There are only four 
Chinese observations, of the 24th, 26th, 29th, and 30th No- 
vember, without latitudes. On the whole we ean place no 
manner of reliance on the orbits of the comets of 240, 539, 
565, 989, 1066, 1097, 1231, 1299, 130], 1351, and 1352. 
14. 1362. Mon. Corr. X. p. 166. Three Chinese observations. The 
two orbits are derived from different. suppositions respecting 
the latitudes. 
15. 1456. The celebrated comet of Halley, of which the period amounts. 
to about 76 years. Pingré I. p. 459. 
16. 1472. From the observations of Regiomontauus, Pingré I. p. 475. 
(15.) 1531. Halley's comet as observed by Apian. Pingré I. p. 488. See 
also especially Halley’s ‘Tabule Astronomice, and his essay 
there inserted, De motn cometarum elliptico. 
17. 1532. Pingré I. p. 492. The once supposed identity of this comet 
with that of 1661 must be abandoned. Méchain, Meém. 
Prés. X. p. 333. Olbers in Hindenburg’s Magazine for Ma-. 
thematics 1787. p. 440. ' 
18. 1533. Pingré L. p. 496. The total diversity of the two orbits suffi- 
ciently shows the uncertainty of both. Struyck, 1753. p. 24. 
Astron. Jahrb. Berl. 18009. 
(9.), 1556. From the observations of Paul Fabricius between the 4th and 
the 17th of March, which cannot be considered as certain ; 
so that we can place little reliance on the resemblance to the 
still less certain elemenis of the comet-of 1264. Pingré f. 
p- 502. 
