Imagens da página

Better taught, thou didst despise

Earthly honour and renown;
Striving for thy calling's prize,
For the never-fading crown.

Rest, from thy labours rest,

In heaven for ever blest!
Early thou hast enter'd there,

Where thy Chief hath gone before;
Now, His triumph call’d to share,

Thou art more than conqueror.

J. W. T.


DECEMBER, 1854. By A. GRAHAM, Esq., Markree Observatory, Collooney. In the earlier part of this month, MERCURY rises two hours before the Sun: the student may thus enjoy a sight which many an ardent lover of astronomy (and among the rest Copernicus) never witnessed. Its intense and silvery light, its very minuteness, and the difficulty of obtaining a glimpse of it with the naked eye, tend to inspire an interest from age to age perhaps unsurpassed by any of the other planets. The revelations of the telescope, and its handmaid analysis, in this case, as in many others, considerably heighten that interest. We insert a brief summary of what is now known concerning this planet. As it revolves round our central body in an orbit considerably within that of the Earth, it presents successively all the phases of the Moon, but in a reversed order. After inferior conjunction, it appears as a fine crescent on the western side of the Sun, and gradually recedes, diminishing in diameter, but increasing the relative magnitude of its illuminated parts, until it attains its greatest western elongation from the Sun, between 16° and 29°, when its form is that of the Moon at the end of her third quarter. After this it becomes gibbous, approaching full toward superior conjunction, and is soon lost in the Sun's rays, to reappear on the eastern side, and reverse the series of changes ---full, gibbous, semicircle, crescent,-until it again reaches inferior conjunction, after a lapse of about one hundred and eighteen days: this interval is termed a synodic revolution. As it moves nearly in the plane of the Earth's orbit, and we consequently view its path very obliquely, the planet seems to oscillate on either side of the Sun's disc nearly in an arc of the ecliptic, whose mean value is 45°; the oscillation from left to right, that is, from east to west of the Sun, being performed in less time than that in the opposite direction. With the exception of the small bodies between Mars and Jupiter, thirty-one of which have now been registered, Mercury is the smallest primary planet in our system. His diameter is 3140 miles, about two-fifths of the Earth’s diameter, not quite once-and-a-half the diameter of our Moon. Of course its volume is to that of the Earth nearly as the cubes of two and five; that is, this planet is sixteen times less than the Earth: but it is composed of materials upwards of two-and-a-half times denser, so that the Earth is little more than six times weightier than Mercury. It is worthy of remark, that the mean density of this planet is about equal to that of its cognominal metal. Our readers need not to be informed that there is no more ground for inferring that mercury is the material of which this planet is composed, than a distinguished philosopher of our own times has for arguing that Jupiter is a sphere of water, from the fact that his mean density is five times less than that of the Earth, or almost precisely equal to that of water. Nor are we to infer that, because the Sun's light and heat at Mercury are nearly seven times greater than at the Earth, his seas, if seas there be, are huge caldrons of boiling water: atmospheric influences may so modify it as to make this planet as suitable for habitation as our own. The length of the day differs very little from ours. Mercury rotates in 24h. 5m. 28s.; the Earth in 23h. 56m. 4s. : the motion of the latter round the Sun makes the length of the day 3m. 56s. greater than the time of rotation; the more rapid motion of the former causes a difference of about sixteen minutes between the solar day and the sidereal, Themean distance of this planet from the Sun is 364 millions of miles; to this corresponds the period of revolution, eighty-eight days, by the third of Kepler's Laws: "The squares of the times of revolution are as the cubes of the mean distances from the Sun.” Analysis has shown that this proportion is only approximate, as it does not take into account the reaction of the planets upon the Sun. Compared with the larger planets of our system, the orbit of Mercury is very eccentric: his greatest and least distances from the Sun differ by 15 millions of miles; they are, in round numbers of millions, 44 and 29, respectively. The orbital motion is upwards of one hundred thousand miles per hour. Knowing the mass and diameter of this planet, relatively to the Earth, the inference may be easily deduced that a body at its surface weighs one-tenth more than would the same body at the surface of the Earth,

MERCURY is now receding from the Earth and Sun. The distances from the former on the first and last days of this month, are 84 and 132 millions of miles ; and from the latter, 32 and 44 millions, respectively. On the 2d, at 2h. in the afternoon, he will be at his greatest northern distance from the plane of the Earth's orbit; on the 26th, at lh, in the afternoon, in that plane. The form of the

planet will be a crescent till noon of the 7th, when he will have reached his greatest western elongation, 21° : after this it will be gibbous. Seen from Mercury, Venus is receding from the Sun westward, and is increasingly large and splendid. Somewhat eastward of Venus are Mars and Jupiter. The Earth, though far inferior to Venus, is a fine object, apparently approaching the Sun on the eastern side. Saturn is very close to the Earth.

Venus is too close to the Sun, and too distant from the Earth, to be visible. She will be in superior conjunction with the Sun on the 13th, at half-past ten in the morning. Mercury is the evening star to Venus. Toward the end of the month he will have reached his greatest elongation; and, as he is approaching Venus, he will then and subsequently increase in brightness. Mars and Jupiter will have nearly the same appearance as from Mercury.

MARS is near the Sun on the eastern side.

JUPITER is still visible after sunset; but is too low to bear examination with telescopes of high power.

SATURN will be in opposition to the Sun on the 4th, at 7h, in the afternoon. On that night he will be considerably obscured by the proximity of the full Moon. A few nights will suffice to restore him to his splendour; and those who have the means will do well to take advantage of the favourable position, and feast their eyes and their minds by contemplating this singular product of creative skill. At the end of the year he will be only 2° distant from Aldebaran. His ring appears almost precisely as it did in November. The minor axis is one second seven-tenths greater than the diameter of the sphere: thus, the southern edge of the latter will appear on the ring, nearly one second within its edge.

URANUS will cross the meridian, at an altitude of 54°, on the evening of the 1st, at four minutes past ten; on the 16th, at three minutes past nine; and on the 31st, at three minutes past eight.

NEPTUNE will cross the meridian, at an altitude of 31o, on the evening of the 1st, at eighteen minutes past six; 16th, at twenty minutes past five; 31st, at twenty-two minutes past four. His distance, on the 16th, is 2,871 millions of miles. To traverse this space, light requires 4h. 9m. 45s.: it comes from the Moon to us in less than a second and a half.

The Sun enters Capricorn on the 22d, at 3h. in the morning, and the Winter quarter commences.

"Ah! why reposest thou so pale,
So very still in thy white veil,

Thou cherish'd fatherland?
Where are the joyous lays of spring,
The varied hue of summer's wing,

Thy glowing vestment bland ?

“ On all thy trees, on every bough,
Thousands of crystals sparkle now,

Where'er our eyes alight;
Firm on the spotless robe we tread,
Which o'er thy beauteous form is spread,

With glittering hoar.frost bright.

“Our Father kind, who dwells above,
For thee this garment pure hath wove,

He watches over thee;
Therefore in peace thy slumber take,
Our Father will the weary wake,

New strength, new light to see."


[blocks in formation]


Rises. Sets. Rises. Sets. Rises. Sets. Rises. Sets. Rises. Sets. h. m. h. m. h. m. h.m.h.m. h. m. b. m. h, m. h. m. h, m. 17 36 4 2 7 45 3 537 55 3 43 8 6 3 32 8 19 3 19 117 48 3 59 7 58 3 498 9 3 38 8 21 3 268 35 3 12 217 56 4 18 6 3 518 17 3 40 8 30 3 278 45 3 12 31 7 59 4 8.8 8 3 58 8 19 3 47 8 32 3 35 8 46 3 21




[blocks in formation]




A soldier's trust, 5051

Chaucer, biographic sketch of, 193
Abyssinia, deaths and funerals in, China, a journey in, 264

Chinese insurgents, an imposture of
Abyssinian Priests, described, 372 the, 118
Africa, Central, Dr. Vogel in, 253 Clement VII., a scene in the life of,
Africa, Southern, Dr. Livingston's 565

journey through the interior of, 537 Coinage, English, account of, 454
America. Destruction of the stock Cologne, moral of the Cathedral of, 534

of Messrs. Harper, publishers, of Coloured glass windows, hints for, 154
New-York, by fire, 74-particulars Comet visible in March and April of
of the rise of Messrs. Harper, 74- this year, remarks on, 240, 284-in

an American erratum noticed, 138 August of last year, 333-parabolic
Anathemas, specimens of: Jewish, 205 orbits of comets, 381
-Papal, 206

Constantine the Great, note respecting,
Anecdotes : Archbishop Usher and

Henry Cromwell, 6-Mrs. Opie, 90 Cowper, biographic sketch of, 433, 483
An old maxim, 426

Crystal Palace, Sabbath-keeping in
Armenia and Asia Minor, the Gospel

the, 474-books on the, noticed, 476
in, 293
Assyrian weights, 20

Dante, biographic sketch of, 337
Asteroids, tabulated views of, 45, 94– Dickens, caricature of religion by, 207

table of the orbits of, explained, 140, Dionysius, St., of Zante, history of,
189--the asteroid “Bellona," 238

Astronomical phenomena. See Celes- Dryden, John, biographic sketch of,
tial objects.

Athens, St. Paul at, 249

Eagle and swan, 64
Baird, Sir David, noble endurance of, Eagles, anecdotes of, 129

as a captive, 505--honourable con- Eclipse of the moon, 237, 525-of the
duct of, as a conqueror, 553

sun, 237, 526
Becket, Tbomas, referred to, 107

Educated men, obligations of : an ad.
Boccaccio, biographic sketch of, 289

dress, by the Rev. John Allison,
Brackenbury, R. Č., Esq., mentioned,

New Brunswick, 156

Embalming of Joseph, 368
Buchanan, George, biographic sketch Episcopius, Simon, biographic sketch
of, 385

of, 97
Buddhist Priest, death and funeral of Euler, biographic sketch of, 529
a, 116

Evangelical religion, popular carica-

tures of, 207
California, the geysers of, 25

Exercises, 43
Catacombs, newly-discovered, in the
kingdom of Naples, 230

Fashion, the miseries of, 281
Caucasus, prophets of the: Elijah First-fruits, in the Church of England,

Mansour and Khasi-moullah, 324- explained, 56
Schamyl-bey, 360

Fletcher, Mrs., the "Life" of, a fa-
Celestial objects, 44, 93, 140, 189, 236,

vourite book with the ex.Queen of
284, 333, 380, 430, 478, 525, 569 the French, 91

« AnteriorContinuar »