22 
SIR J. F. W. HERSCHEL’S CATALOGUE 
Eo. 
surprising that it should not have been again perceived without some time and 
trouble bestowed, and in clear weather. 
1707 h. 527=11. 48. M. Auwers, owing to an erratum in P.T. (see List of Errata), 
makes the R.A. of II. 48 two minutes too great, and is thus led to doubt its 
identity with h. 527. There still remains the rather considerable disagreement 
of 5' in P.D. D’Arrest found neither of these nebulae; hut there can be no 
doubt of the existence of one at least, in or near the place here given. This is 
not the nebula seen by Lord Rosse “ nearly in contact with h. 526.” This latter 
(described already by h. as “ bi-nuclear ”) was seen by R. as distinctly double. 
1712 h. 531=M. 67. Discovered by Oriani. 
1720 h. 535=11. 823. W.H. describes this nebula as “Round;” h. as “much ex- 
tended,” while Lord Rosse saw it as bi-nuclear, or a double nebula joined by 
faint nebulosity. Is it separating into two, like Biela’s comet % 
1735) h. 542 and II. 557. The descriptions are irreconcileable, and they must be two 
1736) distinct nebulae. The R.A. of h. 542 was not observed, and its P.D. is set down 
as “hardly more than conjectural,” having been looked for by working list as 
II. 557 and set down as such. 
1742 h. 545=11. 834. Misprinted II. 844 by Auwers in the Catalogue, but the num- 
ber is correct in his general list of the nebulae by numbers and classes. 
1743 h. 546. Not seen by Lord Rosse in one observation. Examined sweep 21 (h.) and 
found all right. 
1756 III. 291=D’Arr. 60. These are assuredly one and the same nebula. Auwers’s 
declination of III. 291 (+27° 7') should be +26° 7'. 
1773 h. 565=111. 61. The P.D. according to H. is 70°. 
1788 II. 708. Owing to an erratum in the determining star in Phil. Trans, (see List of 
Errata), Auwers has given the place of this nebula for 1830 R.A. 9 h 12 m 39 s ; 
P.D. 39° 17', instead of 6“ 29 s ; 47° 20'. 
1791) 
1794 jh. 577 ; h. 578. Not seen by Lord Rosse in one observation. (See next note.) 
1792 D’Arrest 62. This nebula must surely be variable, as it is inconceivable else that 
it should not have been seen by h., when h. 578, to which it is almost close, 
was observed and its place taken. D’Arrest says, “ Fugerat Herschelium nec- 
non me anno 1862.” Neither of the three (Nos. 1791, 1792, 1794) were seen 
by Lord Rosse. Sweep 59 (h.) and the reductions re-examined. Found all clearly 
written and all correct. 
581, 582 ; 581, a , b, c, d, 582, a, b , c, d , e,f \ g ; D’Arr. 63. Of this very complex 
group of 15 nebulae or “knots” (as they are called by Lord Rosse), six have 
been determined from his diagram, and six more by the aid of notes subse- 
quently furnished me from the records of the observatory at Birr Castle, con- 
taining differences of R.A. and P.D. from one or other of the former. These 
1804) h 
to 
1815 
1817 
1818 
1821 
