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The following Table shews the State of the Standard Catalogue

at this present Time, Sept. 1813.*

*

N. P. D. of Stars for the beginning of the Year 1813.

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200

I Polaris

141 21,75 + 0,02 2 B Urs. min.

90 15 4 48,95 0,00 3 Cephei

40 20

5 30,70+ 0,40 4 Urs. inaj. 60 27 14 31,46 - 0,04 5 « Cephei 40 28 12 12:47 | + 0,12 6 la Cassiop. 40 34 29 22,73 0,10 7 ly Urs. maj. 50 35 15 55,27 + 0,17 8 7 Draconis

90 38 29 3,65 - 0,08 9 Im Urs. maj. 80 39 44 57,88 + 0,08 IO a Persei

40 40 48 52,671+ 0,30 II Capella 80 4 12 20,47 -0,49 12 ce Cygni 800 45 22 56,92 = 0,27 13 « Lyræ

100 51 23 0,43 - 0,29 14

Castor 30 57 42 46,73 + 0,16 15 Pollux 40 61 31 56,34

0,23 16 la Tauri

650 61 34 43,66 + 0,15 17 - Androm.

35 61 56 29,61 The same as in former Catalogue, 18 a Cor. Bor.

- 0,27 and probably true to o",5 or less. 19 - Arietis

50 67 25 36,49 - 0,27 20 Arcturus 80 69 50 19,08 + 0,04 21 Aldebaran 56 73 52 35,36 + 0,18 22 B Leonis

2074 22 57,31 +0,07 23 - Herculis

50 75 23 14,04 + 0,07 24 - Pegasi

2075 47 51,70+ 0,07 25 Regulus 5077 7 22,69 -0,25 26 le Ophiuchi 70 77 17 39,16 - 0,50 Doubtful to o”,5. 27 - Aquila 100 81 36 58,66

0,22 Doubtful. 28 « Orionis

30 82 38 15,72 0,24 Doubtful to o”,5. 29 2 Serpentis 70 82 58 39,26 +0,39 3011 Procyon 40 84 18 14,36 0,361

C

| The N. P. D. of Procyon in the former Catalogue was 15",03; this was from a mistake of 1",o committed in adding the annual variation, it should have been 14",03.

Though the Observations

were given to the Society, as by the date of the paper, yet, by the permission of the President and Council, they were extended till the time That they went to the press.

Rr2

Remarks on the above Observations.

a Lyræ and « Aquilæ having been supposed subject to a sensible parallax, I have, as I mentioned before, reserved them for future examination. The observations which I have already made on these stars, and particularly on « Aquilæ, are not

, incompatible with this supposition, though I cannot at present

I venture to decide whether the small discordances I have met with are to be attributed to any regular cause, or are only accidental.

Whenever I speak of the degree of exactness to which any result may.

be depended upon, I allude only to the mechanical measure given by the instrument. I have every reason to believe, that if two fixed and well defined points could be placed in the plane of the meridian, I could, in a very short time, measure their angular distance to within a tenth of a second; but astronomers must be well aware that the stars are not presented to us in this simple form, and that the sources from which small errors may arise, either in the observations themselves or subsequent computation, are so very numerous, that anomalies will occur even to the most careful observer, which he will in vain endeavour to explain. With respect to the parallax of a Lyræ, I might observe that it is a star so badly defined, and so little adapted for exact observation, that a parallax of half a second would not be easy to determine even with the Greenwich circle.

a Aquilæ is in some respects a better star for observation, but only half its actual parallax would be sensible in declination.

There are several other stars much better adapted for this investigation, even should their distance be supposed more than double, such are Polaris, 9 Ursæ maj. a Cygni, B Urs. min. and y Draconis; now in these I have not hitherto found any sensible parallax; occasional discordance has frequently suggested some slight hopes, but these have always been disappointed by continuing the observations. It is, however, useless now to anticipate this subject farther.

Those stars which are in the general Catalogue, but which do not form part of the standard Catalogue, I presume to be exact to the nearest second.

I have not included any star in the standard Catalogue south of the equator, on account of the uncertainty of refraction,

కనుక మనకు తమకు

XXXIII. Observations of the Summer Solstice, 1813, with the Mural Circle, at the Royal Observatory.

By John Pond, Esq. Astronomer Royal, F. R. S.

Read July 8, 1813.

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- 38

26 44,728 58,966 32 20,4 + 1,0l 28 6 59,966 32 21,4

22 16,2

0,6 0,6 0,6 0,6

56,7

57,6 59,6

18 12,1
14 32,4
8 26,71

1,91
0 32, 이
2 41,1

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June 1029,57 62 690 30,3 OLL 67 14 21,9

1129,81 64 71 29,6 O UL 66 38 18,9
12 29,70 64 74 30,1 O LL 67 5 48,1
13 30,02 61 | 66 30,9 O UL 66 30 36,9
15|29,62 6066 30,1 O LL 66 56 2,3
2130,15 57 60 30,0 O UL 66 16 9,3
23 30,17 56 59 30,8 OLL 66 48 7,4
2530,185964 29,4 O UL 66 18 47,8
27 30,07 | 04 | 70 30,2 O LL 66 54 6,5
28 29,94 6167 29,7| O UL 66 25 9,0

29 29,75 64 74 30,00 LL 66 59 32,2
July 1 29,67 62 65 29,6 O UL 66 35 7,1
2/29,75 60 62

31,8 O LL 67 10 44,8

1

31 22,1 lis 46,5

22,1 15 46,5
22,1 15 46,4)
22,1 15 46,3
22,1 15 46,1
22,1 15 45,8
22,1 15 45,6
22,1 15 45,6
22,1 15 45,6
22,1 15 45,6
22,1 15 45,5
22,1 15 45,5
22,1 15 45,51

0,6 2,61 0,61 0,6 0,6 0,6 0,6

18,2 + 1,0 19,1 + 1,0 21,1 + 0,91 19,0 + 0,7 22,6 0,1 20,0 0,3 21,6 0,3 21,2 0,2 23,3 0,1 20,0 0,0 20,9 + 0,3 21,0 +03+1

57,5
I 1,1
o 58,5
I 0,1
o 59.7
1

1,8
0 58,5
o 59,4

59,5

O 57,7
0 58,6
I 0,51
0 58,21

1,01
o 58,2
o 59,81
o 59,51

1,7
o 58,5
o 59,7
0 59.91

6 29:3

19,21 20,1 22,01 19,7 22,5 19,7 21,3 21,0 23,2 20,0 21,2 21,5

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9 0,41 II 56,1 IS 0,7 23 9:51

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Mean Obliquity

23 27 49,5 * Mean Obliquity at Summer Solstice, 1812 23 27 50,5

Therm.

Barometer.

1813

Refraction.

Observations as given

by the instrument.

Equations for N. P. D.

Equations for Zenith

Distance.

Semidiameter of the O by

Nautical Almanack.

Reduction to the Solstice,

Solstitial Zenith Distance

with Parallax.

Solstitial N. P. D. with

Parallax.

Correction for O's Lat.

Solstitial Zenith Distance corrected for O's Lat.

Solstitial N. P.D.corrected

for O's Lat.

In.

Out.

Mean of Two Observations or Mean Obliqui y, Jan. 1, 1813

23 27 50,0 * I avail myself of this opportunity of correcting a very small error that was made in computing the summer solstice of 1812. The correction for the sun's latitude should have been o”,6 instead of o',9, and should have been applied with the contrary sign. The obliquity thus corrected will be 23° 27' 50",5

PRESENTS

RECEIVED BY THE

ROYAL SOCIETY,

From November 1812 to July 1813,

WITH THE

NAMES OF THE DONORS.

PRESENTS.

DONORS.

1812.
Nov. 5. A Description of the Collection of ancient Marbles The Trustees of the Bri-

in the British Museum with Engravings. Part I. tish Museum.
London, 1812.


A Treatise on Theatres, by George Saunders. Mr. George Saunders.
London, 1790.


Tracts on Mathematical and Philosophical Sub- Dr. Charles Hutton.

jects, by Charles Hutton, LL.D. and F.R.S.
London, 1812. 3 Vols.

80
The Elements of Botany, or Outlines of the Natu. Dr. Benj. Smith Barton.

ral History of Vegetables by Benjamin Smith

Barton, M. D. Prilardelphia, 1812. 8°
Elements of Chemical Philosophy, by Sir Hum Sir Humphry Davy.

phry Davy. Part I. Vol. I. London, 1812. 8°
Essai sur la Rage, par M. J. F. A. Lalouette. 8° Mr. J.F. A. Lalouette.
Institutions de Physique, par B. G. Sage. Paris, Mr. B. G. Sage.
1811. 3 Vols.

80
Of the Circle and the infinite Incommensurability James Glennie, Esq.

of its Area to the Square of its Diameter, with
a Demonstration of Dr. Matthew Stewart's 420

Proposition, by James Gleunie, Esq. F. R.'S.
The Speech of His Royal Highness the Duke of The Editor.
Sussex in the House of Lords, April 21, 1812.


An Account of a Case of Recovery, after an ex- Mr. William Maiden.

traordinary Accident, in which the Shaft of a
Chaise had been forced through the Thorax,
by William Maiden. London, 1812. 4°
Eloge Historique de M. Sabatier, par M. Percy. Mr. Percy.
Paris, 1812,

80
Della Cometa del 1811, osservata nella Specola Mr. Piazzi.
di Palermo, par Gius. Piazzi.

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