صور الصفحة
PDF
النشر الإلكتروني

Astronomical Occurrences

[ocr errors][ocr errors]

In JANUARY 1829.
In once more directing Time's TELESCOPE to a
survey of the starry heavens, we would again caution
our youthful readers not to suffer the mind to repose
in this magnificent display of creative wisdom and
power; for, while contemplating that infinitude of
suns and systems—all peopled with sentient beings,
capable of glorifying the great author of their exist-
ence-how delightful to dwell upon the munificence
of him who created, sustains, and regulates the whole!
DANTE, in his PARADISO, thus characterizes the
harmony and magnificence of the Universe :-

Eternal Wisdom and eternal Love,
Joined with interminable Power above,

Union ineffable, in bliss supreme,
Give to existence this stupendous whole,
Wbere'er the eye can reacb, or soaring soul

Extends around its intellectual beam.
Unrivalled order and celestial grace,
Seen through the stages of unbounded space,

Whene'er the mental eye, with steady view,
Surveys its glory, to the heavenly King
Lifts the rapt soul on Contemplation's wing,

And ev'ry power expands with rapture new.
Now ye that hear the heav'nly muse's voice,
Pursue her journey through the op’ning skies,

Where the first motion wheels her mighty round,
And whirls the planets with resistless sway;
Then think of Him whose power yon orbs obey,

In self-enjoyment wrapt, and bliss profound.
Behold yon shining path obliquely run,
Where, with bis glorious retinue, the sun

Marshals the seasons, and conducts the year:
What wisdom in the Power that taught his ray
To warm the subject world with tempered day,

Not coldly distant nor oppressive near.
Had any other circuit been assigned
For this ætherial cavalcade to wind,

In frost to slumber or to sink in fire,
Had been the lot of all sublunar things :
Here Contemplation rests her weary wings,

And stops awhile to tremble and admire.

BOYD.

Obliquity of the Ecliptic. This expression denotes the angle which the ecliptic makes with the equator, and which is subject to a small annual variation. The nature and magnitude of this in general has already been explained in our previous volumes: we shall, therefore, only insert in this place the measure of that obliquity for the usual epochs during the present year.

January.. Ist, the true obliquity is 230 27' 33.1"
April... Ist

......... 23 27 33.6
July

............. 23 27 32.7 October. Ist

23 27 33.4 December 31st ...

23 27 32.6 January.. Ist, the mean obliquity is 23 27 42:9 The equation of the Equinoctial Points at those respective times is January.. Ist

+ 3.8"
April Ist
July Ist
October :. Ist

0:6
December 31st

22

Ist .....

....

+ 2.3 +0.7

SOLAR PHENOMENA. The Sun enters Aquarius at 44 m. past 5 in the morning of the 20th of this month; and he rises and sets, during every fifth day of the same period, as in the following Table. These times are computed for the meridian of the Royal Observatory, and a slight correction is therefore necessary for reducing them to any other place east or west of that meridian. This is done by converting the difference of longitude into time, at the rate of 15 degrees to an hour, and either adding the result to the above hour, or subtracting it from it, as the place is east or west of the first meridian. The time for any intermediate day may also be found by proportion, as already explained in our former volumes.

1

.... 59

3

57 51

7

[ocr errors]

.... 31

TABLE Of the Sun's Rising and Setting for every fifth Day. January 1st, Sun rises 5m, after 8, sets 55 m. after 3 6th

8
Ilth

7
3

4
16th

9

4
21st

44
7 16

4
26th

37
7 23

4
31st

29
7

4 Equation of Time. The obliquity of the ecliptic and the unequal motion of the earth in its orbit create a difference between apparent and mean time,except on certain days in the year, when they both coincide. The former of these is that indicated by a good sun-dial; the latter by a well-regulated clock. The equation of time is an expression employed to denote the difference between them; and is to be employed when it is requisite to find the one from the other, which is done by either adding or subtracting the equation, as the case may require. The correction for any intermediate day must be found by proportion, according to the rule already given. Referring, therefore, to our former volumes for more particular information on the subject, particularly those for 1814, 1816, 1823, and 1824, we shall merely insert the value of the equation for noon of every fifth day.

TABLE
Of the Equation of Time for every fifth Day.

Thursday Jan. 1st, to the time by the dial add 3 57
Tuesday
Sunday
Friday..
Wednesday ..21st.

11 43
Monday
.26th.

12 56
Saturday ...31st.

m. 8.

6th...... 11th..... .16th......

6 15 8 21 10 11

[ocr errors]
[ocr errors]

13 50 LUNAR PHENOMENA.

Phases of the Moon. New Moon .... 5th day, at 52 m. after 3 in the afternoon First Quarter.. 12th........18. 7 in the morning Full Moon ....20th. .17 Last Quarter .. .28th, .21

5...

0...

[ocr errors]

10

.........

Moon's Passage over the Meridian. As the transit of the Moon affords the means of one of the simplest astronomical observations, we shall insert the times of a few of the most favourable for each month, for the sake of our young readers who may be disposed to exercise themselves in such pursuits. It may, therefore, be necessary to remind some of them, that the times specified are those answering to the first meridian of Great Britain; but these may readily be reduced to any other place, by means of the difference of longitude and the Moon's hourly motion. January 9th, at 36 m. after 3 in the afternoon 10th

29 Ilth 19

5 12th

6 13th

7 in the evening 14th 50

7 15th 40

8
16th 30

9
17th 19 ......10
18th 8 ......11
27th 59 4 in the inorning
28th 45

5
29th 34

6 30th 26

7 31st 21

8 PHENOMENA PLANETARUM.

Phases of Venus. The phases of this beautiful planet are subject to change, like those of the Moon, which arises from her various positions and distances in reference to the Sun and the Earth. Like other astronomical pbenomena, they are susceptible of being correctly calculated, the method of doing which has already been explained in Time's Telescope for 1819. We shall, therefore, leave these computations for the exercise of such of our youthful readers as choose to perform them, and in sert the results for each month.

Illuminated part =

9.90729 {

2.09271

January

Ist

Eclipses of Jupiter's Satellites. The most useful information on this subject having been inserted in our volume for 1818, we shall refer to it in preference to repeating it here, and merely state the times of such of these eclipses as will be visible at the Royal Observatory this month. As these are recorded in mean time answering to the first meridian, a slight correction in these respects will be requisite for other places, which may be easily made in the usual way.

Immersions.
First Satellite 29th day, at 12 in. 2 s, after 6 in the morning
Second Satellite, 10th 13.. 44 ... 6..

Form of Saturn's Ring. The apparent form of this ring is subject to a slow change, the method of ascertaining which has been explained at page 52 of Time's Telescope for 1819. As this variation is only small, we shall merely insert the comparative magnitudes of the two axes for the first day of every third month. When the sign + is prefixed to the conjugate axis, it is the northern side of the ring that is visible; but when -- is employed, the south side of the ring only can be seen.

1.000
Conjugate axis = -0.366
Conjunction of the Moon with the Planets and Stars).
January 1st, with y in Libra....at midnight

6th B .. Capricorn.. 6 in the morning
15th ....18 Taurus l in the afternoon
15th

Taurus
20th .22 Cancer ....ll at night
29th

Libra 9 in the morning

Other Phenomena. Mercury will be in his superior conjunction at a quarter past 5 in the morning of the 14th; Saturn will be in opposition at 45 m. past 2 in the morning

January 1st {Toansverse axis =

28 ..

[ocr errors]

1 We restrict the conjunctions in this place to stars of the first four magnitudes.

« السابقةمتابعة »