A

I,e precedenti osservazioni hanno presentato qualche difficolta a cagione della forma allungata del nucleo della Cometa. Come punto di mira si 6 procurato ogni volta di prendere il centro della massa nebulosa fusiforme, bench6 non fosse certa la coincidenza di questo punto col centro di gravita.

Le riduzioni sono state eseguite colla cooperazione del Dr. Porro. Furono fatte anche annotazioni sull' aspetto della Cometa, e fu delineato il contorno delia coda e delle sue varie appendici: ma la pubblicazione di questi risultati richiede un certo numero di disegni e percio si riserva ad un' sltra occasione.

Osseriatorio Reale di Hrera in Milano 1884 Settenibre 24. G. K SckiqtuzreZli.

Ohset+vations of Coinet 1884 I1 (Barnard) m a d e a t t h e R o y a l O b s e r v a t o r y , C a p e o f G o o d H o p e ,

(Communicated by David GiZl L L. D. F. R. S. Her Majesty's Astronomer).

The following observations were made, with the 7 inch Equatoreal and Repsold-Filar-Micrometer, by Mr. W. H. Finlay, Chief Assistant. The comet was so situated that meridian observations of the comparison stars could always be secured with the transit circle within a few nights after their comparison with the Comet.

The observations are corrected for the effects of refraction.

The Comet throughout presented the appearance of a small diffused nebulous mass. A nucleus was seen by glimpses on July 28, but the bright moonlight on following nights prevented more than a suspicion of its existence. About the end of July the point of greatest condensation (within which the nucleus had been seen on July 28) was slightly towards the following part of the mass; this was

1884 I CapeM.T. ~ d R A .

July 24 26 2 7 28 29 30

Aug. I

5 6 7 8

'3 14 ' 7 '9

I 1

2 0

2 2

23 Sept. 15

I 7 2 1

2 2

I O ~ 8" 8?1 10 38 4.0 1 0 54 54.1 I I 6 15.8 I 1 I 0 32.2 11 5 1 5 . 7 1 0 '9 53.3 9 35 49.5 9 53 49-7 10 10 18.4 10 10 5.0 1 0 4 50.4 10 14 35.2 9 45 9.5 9 47 36.8

10 10 4.8 10 1 2 46.7 10 26 1.8

10 19 31.8 I 0 27 13.5 9 44 44.1 10 1 2 12.9

1 0 4 39.6

-o'"I 3Soo

f o 10.09 -0 14.11

+o 4 7 4 ' -0 7.04 4-0 32.05 +o 30.12 +o 21.60 -0 20 .07

-0 22.80 + O 23.13 -0 21.98 +o 29.46 - - 0 '7.79 -0 25.26 +o 10.08 +o 35.86 +o 11.50 -0 51.09 -0 16.20 +o 54.93

+4 30.38

4 - 1 0.99

A NPD.

-t-6'57:1 --6 29.0 - 1 14.3 +6 33.3 -2 26.8 +I 59.5 + I 31.0 +o 53.5 +2 18.8 + I 31.6 -0 46.7 - I 2.6 -3 30.7 -3 17.2

t o 0.8 -2 37.2 -0 12.9 +4 52.3 +5 4.2 +5 7.9 +z 12.9 -2 26.6 4-0 7.3

the point observed. In '4ugust the appearance of the Comet was reduced by moonlight to a small round mass slightly brighter towards the centre - the centre of this mass was observed. The Comet presented a similar appea- rance in September and was similarly observed.

An apparent increase of brightness on September 15 and following days, compared with the appearance of the Cornet in the end of August, was very striking. The Comet as a rule was faint and difficult to observe in August, probably from its then being projected on the milky way as a back ground.

Observations of Comet, 1884 I (Pons 1812) have been secured on 43 nights from January 16 to April 29 by Mr. Finlay, and will be published so soon as the meridian observations of the comparison stars have been completed.

Camp.! RA. app.

4.4 4.4

16.16 16.16 16.16 16.16 10.6 16.16 16.16 16.16 20.16 20.16 20.16

16.16 15.16 I 6.8 16.16 16.16 24. I 8 16.16 17.12

12.16

1 2 . 1 2

1 6 ~ 5 m 3 ~ ? 5 6 16 1 0 14.75 16 1 2 41.63 16 15 14.61

16 2 0 33.87 16 26 5.69 16 38 8.32 16 41 24.38

16 48 4.67

16 1 7 52.45

16 44 43.78

16 58 29.35 '7 5 45.67 1 7 9 23.79 ' 7 2 0 47.58 1 7 28 40.96 1 7 32 39.96

I 7 44 44.83 I 9 2 0 3.95 19 28 O. ; I

19 41 16.36

I 7 40 44.45

'9 43 2 5 . 0 2

log f.p.

8.61 7 8.668 8.703 8.725

8.727 8.644 8.5 30

8.633 8.633

8.734

8.580

8.622 8.646 8.580 8.576 8.635 8.640 8.667 8.6 I 7 8.614 8.626 8.513 8.587

NPD. app,

127°~4'491'1 1 2 7 15 34.1 1 2 7 '5 35.5 1 2 7 '5 30.4 1 2 7 1 5 15 .1

1 2 7 14 46.8 1 2 7 13 19.6 1 2 7 7 6.2 1 2 7 4 44.4 1 2 7 2 3.0 126 59 9.8 126 48 5 .2

126 38 44.6

126 14 54.6 126 o 4.9 1 2 5 5 2 10.9 '25 34 24.9

119 37 5.7 1 1 8 57 1 7 . 5 ' 1 7 35 48.0 1 1 7 I 4 '9.4

126 33 2 5 . 7

' 2 5 24 54.1

log f. p. 1 Star

8.580 8.839 8.987 9.072 9.107 9.079 8.59' 7.699 8.447 8.708 8.708 8.690 8.820

8.580 8.532

8.833 8.77'

9.236

9.000 8.85 I

9 . 2 7 2 9.225 9.295

n b

Stone 8897 Stone 8913

d

C

E

f g h i k I WZ n 0

P y. 7433 AOe, I9534 '40% '9737 AOe, I9997 4Oe, 20039

2 0 3 2 6 2 9 204

The comet was also observed with the transit-circle by Mr. Finlay on Auguat I 4 and I 6, with the following result :

19 28 48.23 f 3 . 5 7

1884 I Cape M.T. ~ K A app. i NPD. app. , log f. p.

.lug. 141 7h34n'48F8 1 7 ~ 9'" 6'19 1 126~33'57:5 8.681, 8.6441,

~~ ~~ __ .. ~

161 7 34 2 6 0 I 1 7 16 36.39 1 126 2 2 6 6

118 5 5 17.6 - 13.0

N o t e s .

July 24. Comet exceedingly faint and difficult .- hazy. I Aug. 13. Comet faint. 28. Comet much easier to-night; distinct appearance 1 19, Comet very faint;' very difficult.

of nucleus or condensation. 20. Comet exceedingly faint, scarct.,' possible to ob- Aug. I . Comet very faint; bright moonlight. serve at all.

5. Moon very bright, but fair observations. 7 Bright moonlight; air very damp and hazy; Comet I Sept.15. Comet much easier and brighter than when last

very faint. observed.

1 22. Fair observations.

Star

a n' b b'

Stone 8897 Stone 8913

d e e'

Stone 9061

:: k i

Stone 9295 k' R G

C

f

f l 2

n 0 0'

P 4

Yarnall 7433

A d o p t e d R i g h t A s c e n s i o n s a n d N o r t h P o l a r D i s t a n c e s o f S t a r s

o b s e r v e d w i t h t h e C o m e t .

- Mag. KA. 1884.0 NPD. 1884.0

__. __

1 6 ~ 5"'39?80

16 5 40.52 16 10 2.52

16 1 2 2 7 . 7 0 16 1 5 24.88 16 16 47.64 16 19 42.64 16 26 8.91 16 2 5 55.81

16 37 32.44 16 40 50.42

16 48 20.93 16 58 30.01

16 58 48.29 1 7 5 18.69

1 7 2 0 14.28 ' 7 2 8 54.91 1 7 29 21.81 1 7 33 1.39 I 7 40 30.55 ' 7 44 5.16 19 19 48.86

16 3 34.70

16 34 59.59

16 44 18.34

16 58 33.1 7

1 7 9 41.92

+3583 +3.83 t 3 . 8 5 +3.85 +3.84 +3.84 f-3.82 +3.82 +3.84 +3.84 t 3 . 8 3 +3.83 -1-3.84 1-3.84 +3.85 +3.86 +3.86 +3.86 +3.85 +3.85 f 3 . 8 4 4-3.84 f 3 . 8 4 f 3 . 8 3 t-3.82 t 3 . 8 1 -+3.59

1 2 7 " 7'47:'3 5:'7 1 2 7 9 18.1 4- 5.7 1 2 7 2 1 57.9 -4- 5.2 1 2 7 2 7 47.4 -I- 5.2 1 2 7 16 44.8 + 5 . 0 1 2 7 8 52.4 + 4.7

127 1 2 42.6 -t 4.7 1 2 7 I: 44.7 +- 3.8 1 2 7 8 1.6 + 3.8 1 2 7 6 55.4 -i- 3.0 1 2 7 6 9.7 + 3.0 I27 2 23.1 -4- 2.5 I 2 7 0 29.3 + 2.1

126 59 54.7 +- 1.8 1 2 7 3 58.2 +- 0.9 126 56 17.1 i- 0.9 126 49 6.9 + 0.9 126 42 1 j . 1 + 0.2

1 2 7 ' 7 37.2 + 4.7

126 36 43.1 - 0.2 126 14 55.0 --- 1 . 2

126 2 44.1 - 2. I 126 5 17.6 -- 2. I

1 2 5 5 2 26.2 - 2.4 1 2 5 2 9 35.7 -- 3.2 1 2 5 I 9 53.4 -- 3.5 119 32 10.0 - 1 2 . 2

Authority

Measures with Equatoreal 3 Meridian Observations Cape 1884 Measures with Equatoreal 3 Meridian Observations Measures with Equatoreal Stone 8897 Stone 8913 Measures with Equatoreal Measures with Equatoreal 2 Meridian Observations Stone 9061 Measures with Equatoreal 2 Meridian Observations Measures with Equatoreal 3 Meridian Observations Stone 9295 2 Meridian Observations Measures with Equatoreal 2 Meridian Observations 3 Meridian Observations 2 Meridian Observations Measures with Equatoreal 2 Meridian Observations 2 Meridian Observations 2 Meridian Observations Cape and Yarnall AOe, and 2 Cape Meridian Observations 2 Meridian Observations Stone 10673 AOe,, Yarn. 8540 and Cape Merid.

The following Table gives the differences of K.4. and NPD. between the Comparison stars and brighter stars, observed with the IG~uatoreal.

2629 206

8S43 +3'4814 , 2 1 ~ 1 6 ~ 5 3 ~ 1 8 1 8.209 -17'31' 31'2 ~ 0.909 I

2 1 ' 7 59 5 2 - - I 13.75 -0 295 2 1 2 2 41.74 I 8.843 ' - - 1 6 48 48.5 1 0.905 0Ct. I 9 7h31"425 -0"

231 7 41 2 + 2 14.43 +5 19.1 1 2 1 28 18.58 8.594 -16 7 37 91 0.904

; I C

C

d l e l

I 2

3

1 + z m 5 ~ 1 0 -- 1'3018 1 12 I

1

9 --4 2 2 . 0 0 --j 49.5 , 6' Io ' ---z 5 7 . 5 5 ' + 7 5 1 9 Stone 8897 10 ~ - 4 19.75 ---o 5 2 . 0 , Stone 8913

7lIa , + z 55.00 --4 54.6 1 Stone 8913 I 0 1 -l-O 13.101 +3 43.1 e'

Star ~ Mag. 1 A RA. A NPU. Comp. with __ _- .~

l l I I f k k

-0) 4517 --I 55.0 i-0 35.5 -7 10.2

-7 40.7 2 33.5

Stone 9061

< 2

K' Stone 9295

0'

David GiD.

I

2 1 ~ 16~58142 +$19 I - 1 7 ~ 35' I 1:'9 i-2013 j Anschluss an 32 Capr. (Melbourne und Stone)

2 1 26 0.97 +3.18 -16 1 3 17.8 +20.8 AOe, 21457 21 23 52.29 t3.20 -16 48 39 7 +20.7 I Amchluss an Yarn. 9405

Die Beobachtungen verursachten in den letzten Tagen schon bedeutende Schwierigkeiten, so dass ich nicht sicher bin, ob ich nach Verschwinden des Mondes zu weiteren Beobachtungen im Stande sein xerde.

- Strassburg 1884 Oct. 3 I .

Approximate elliptic eleiuents of Comet 1884 I1 (Barnard). I computed a parabolic orbit for this comet in August but was unable to represent the middle place satis-

factorily. As a similar result was found in Europe and as Mr. Stechert's ephemeris in Xstr. Nachr. Nr. 2609 shewed large discordances from my later observations, I have computed elliptic elements with the following result. The observations used, viz. July 2 7 , August 2 2 and September 1 7 , were corrected for parallax from the parabolic orbit. The approxi- mations to Q were not carried as far as perhaps they should have been, but the approximation was quite close enough to shew whether the comet was moving in an ellipse and, if so, to give a very fair value of the periodic time.

T = 1884 August 16.50950 Greenwich M. 'L. JC = 306" 3'40"

i = 5 30 36 1 = 4 54. I Mean Equinox and Ecliptic 1884.0

logn = 0.5017524 9 = 36 34 31 ,IL = 627:"59

Period = 5.6615 years

These elements leave a discordance (C-0) in the middle place of -8" in longitude and - I " in latitude. The month of October, since the Moor. drew away from the evening sky, has been completely clouded until last night Oct. 14, when I secured a fair comparison of the comet with AOe, 2 1 1 5 1 . This observation compared with the above elements gives the discordance (C - 0) :

dg C O S ~ = SO dd = --I 1''

Royal Observatory, Cape of Good Eope 1884 Oct. 15. W. H. FznZay.