Die hier mitgeteilten Elemente des Planetoiden I 909 HF Beriicksichtigt sind die sind aus funf Normalortern erhalten.

Beobachtungen: Wien 18, '91 2 1 , 24, 26, Sept. 6, 8, I0,

The August shower

Die die Helligkeit bestimmenden Groflen sind : g = 10?40 F oTo7 nio = 13m47.

Die Abweichungen der &Torma16rter i1m Sinne B - K sind:

The Perseid shower was not well observed'this year owing to cloudy weather but the partial views obtained of it show that it was a pretty brilliant display with many fine meteors.

At Bristol the first Perseids were seen on JLIIY 1 2 and 13. Near the maximum the only really clear night was Aug. 10 when 52 meteors were recorded between 9h and 1 1 ~ 4 5 ~ p.m. The finest meteor seen on this date and one observed on Aug. 12 were also registered by observers in South Wales and I have computed real pathes:

rigiert werden). Die in A. N. 185.5 gegebenen Beobachtungen I Aug. 2 2 . 5 1 +0!6 sind in der Berechnung nicht berucksichtigt, da sie erst nach Sept. 9.5. i -1.1

Okt. 21.5 t 1 . 4 Nov. 16.26 -0.7

Beendigung der Rechnung veroffentlicht wurden. Sept. 23.0 +z.8 Die erhaltenen Elernelite lauten :

of Perseids 1910.

-

+or7 9 +0.4 11

-0.1 3 +1.4 3 -3.6 I

Date -Greenw. M. T. Magn. Height at first Height at end Path Velocity Radiant Name of meteor

1910 1 u Vera ~ d Vera I l o g n 1 Ab.-Zeit I

i Nov. 19 j 7h491n46579 I t 8 " 55'46!'3 I 0.3656 1 9 ~ 1 7 ~ Z I 1 49 25.66 I 8 43 12.7

3 45 9.64 7 33 51 .4 5 44 5.95

7 I 3 31.4

I 1 40 21.49 1 6 54 50.8

7 42 56.57 j

13 38 56.23 1 6 46 10.4 0.3279 1 7 41

I

j

1 5 7 37 26.14 +6 37 5 7 . 7

I

Aug. 10 l o h 6" > 9 7 5 miles 48 %

54 ))

2 7 ))

45O f 56O Perseid

j log d i Ab.-Zeit I

1910-11 1 ccvera 1 bvera

Dez. 2 1 I ~ ~ 3 2 ~ 2 9 5 6 6 +6" 16'1573 1 0.3202 1 7 ~ 2 2 '

24 0.3176 17 16

2 8 26

30 0.3159 I 7 I 2

Jan. 0.3152 17 10 21 1 0 . 0 2

20 10.34 5 45 .37.r 4 I 9 10.46 5 44 13.9

I 16 10.30 0.3155 17 11

5 40 53.9 6

19 , 1 5 10.27 5 40 3.6 1 9 1 I 4 1 0 . 3 5 5 39 21.4

10 [ 7 13 10.60 I + 5 38 47.3 0.3168 1 7 14

Aug. 1 2

> a 89 miles

51 40 %

9'+ 27'

a Andromedid.

I Ih49"

53 * ) )

The Perseid should theoretically have travelled swifter than the Andromedid but the reverse appears to have been the case. There are certainly great differences in the observed velocities of the individual meteors belonging to one and the same observer.

Bishopston, 1910 Aug. 16. ~~ tV. I;. Demii~g.

The Orbit Elements of Halley's Comet. The epoch 1910 April 20, given in my paper on the

DProvisional Orbit Elements of Comet Halleye, A. N. 4406, and which refers to M, seems to have caused confusion to Messrs. Cowell and Cromnielin.

The date of osculation is not given in my paper, and not at all necessary under the circumstances.

The statement, A. N. 4433, p. 267, ,that Mr. Merfield erroneously gave the date of osculation as 1910 April z o e , is incorrect and misleading.

Perhaps I may be permitted to remark that it is unusual and unnecessary to give the date of osculation in a system of approximate or provisional orbit elements.

1910

Nov. I 3 I 4 15 16 ' 7 18 ' 9 2 0

2 1

2 2

2 3 24 2 5 26 2 7

28 29 30

Dez. I

3 4 5 6 I 8 9

2

a Vera

1 5h 3 5"3 5' 35 5s 36 2 1

36 44 37 7 3i 30 37 5 4 38 IS

39 4

39 5 2 40 16 40 40 41 4 41 28 41 5 1 42 1 5 42 38 43 43 2 5

43 49 44 1 2

44 35 44 58 45 2 1

' 5 4 5 43

38 47

39 28

In the final investigation of orbit elements, in which definitive values are required, then it is necessary to adopt some instant to which the elements refer. This instant may be taken at pleasure and is simply the time at which the perturbations have zero values given to them.

Most computers adopt the epoch of Ji' as the date of osculation, simply as a matter of convenience in statement, but unless mentioned I consider it is erroneous to assume that this epoch refers to both.

Melbourne, 1910 Sept. 20. C. 7. Merjeld.

Ephemeride des Kometen 1910 b (Metcalf).

6 Vera

+21° 5313 2 2 2.3

2 2 11.6

2 2 30.8 2 2 40.7 2 2 50.8 2 3 1.2

23 11.8

23 2 2 . 7

23 33.8 23 45.2 23 56.9 2 4 8.9

24 33.6 24 46.4 2 4 59.5 2 5 12.9 2 5 26.6 2 5 40.5 2 5 54.8 2 6 9.3

26 39.3

2 2 21.1

24 21.1

26 24.1

26 54.8 - t 2 7 10.6

I z h in. Z. Berlin.

log Y

0.3170

0.3206

0.3243

0.3282

0.3322

0.3364

0.3406

log rJ

0.436 I

0.43 56

0.4345

0.4328

0,4304

0.4274

0.4239

Fortsetzung von A. N. 186.79. - Gr .

12mo

__

12.0

12.0

12.0

12.0

12.1

12.1

1910-11

Dez. 9 I 0

I 1

I 2

I 3 I 4 7 5 16 11 18 19 2 0

2 1

2 2

23 24 2 5 26 2 1 2 8

29 30 31

Jan. I

3 4

2

cc Vera

[5h45m43' 46 5

41 I

48 5 48 23 48 41 48 59 49 16

46 26 46 41

41 2 1 41 46

49 33 49 49 5 0 4 5 0 19 50 33 5 0 46 5 0 59 5 1 I 0

5' 2 1

5' 30 5 ' 39 5 ' 46 5 ' 53 5 7 58

[ 5 5 2 2

6 Vera

+ z l o IO.!~ 2 7 26.8 2 7 43.3 2 8 0.2

2 8 1 7 . 5 28 3 5 . 2

28 53.3 29 11.7

29 30.5 29 49.7 30 9.3 30 29.3

31 10.3 31 31.4 31 52.9 32 14.9 32 31.3 33 0.1

33 23.3 33 47.0 34 11.1 34 .35.1 35 0 . 7 35 26.2 35 52.7

+36 18.5

30 49.6

log r log d

0.4199

0.4153

0.4103

0.4050

0.3994

0.3936

0.381 5 Nach einer Mitteilung von Prof. A?. Schorr stimmte nach einer Bergedorfer Beobachtung 19 10 Oktober

Kiel, Bureau der Astr. Nachrichten, I g I o Okt. 3 I .

Ephemeride noch vollstandig. Der Komet hatte einen Kern 1 r m 5 .

M. E M .

Gr.

I 2mr

1 2 . 1

1 2 . 1

1 2 . 1

12.0

1 2 . 0

1 2 . 0

I die

I n h a1 t zu Nr. 4452. E. Hcrt,-rp7lrizg. Vorschlag zur Festlegung der photographischen Graflenskala bei auflerfokalen Aufnahrnen. I 77. - 7. Pziioux. Corn& 191oa et petites Planktes. 183. - Beobachtungen des Kometen ~ g ~ o b (Metcalf). 187. - IT. Orten. Epherneride von (447) Valentine. 187. - N. Ha$onozuicz. Verbesserte Elemente und Ephemeride des Planetoiden 1909 HF. 189. - W. F. Dcnning. T h e August shower of Perseids 1910. 189. - C. 7. MerjeZd. The Orbit Elements of Halley's Comet. r g r . - M. E6ell. Epherneride des Korneten 191ob (Metcalf). 191.

Geschlossen zgro No". 3. Herausgeher: H. K o b o l d . Druck yon C. Schaidt (Georg Oheim, Alfred Oheim). Expedition: Kiel, Moltkestr. 80.