ASTRONOMICAL PHENOMENA.

JUNE, 1855.

By A. GRAHAM, Esq., Markree Observatory, Collooney.

MANY a telescope will, in the course of this month, be pointed towards Aquarius, in search of the periodic comet discovered by De Vico at Rome, on the 22d of August, 1844. On the 6th of the following month, four days after the perihelion passage, it was seen at Hamburg with the naked eye. Its orbit is an ellipse, which at the perihelion is within 113 millions of miles of the Sun, and at the aphelion is 477 millions of miles distant: so that at the former point the comet is not far from the orbit of the Earth; at the latter it is near the orbit of Jupiter. Its revolution round the Sun is accomplished in about 5 years 170 days, and it must have been again in the vicinity of the Earth's orbit in February, 1850; but we were then on the opposite side of the Sun, and could not see it. It now returns under circumstances tolerably favourable for examination, though it will not be so bright as in September, 1844. Its approaching perihelion passage will be somewhere about the 9th of August; the perigee, or minimum distance from the Earth, 55 millions of miles, a few days earlier. The distance from us on June 1st is 80 millions, on July 1st 60 millions, of miles. On the 1st of June it will be apparently close to Jupiter; on the 17th, near Neptune.

MERCURY is as charming as his appearance to the naked eye is rare. His intensely brilliant silvery disc will be gibbous till the 15th, the time of his greatest elongation, after which he will be like the Moon in her first quarter. On the evening of the 16th he will be near the Moon, then a thin crescent. His diameter will then be about half that of Venus.

VENUS is increasing in size and splendour. Her apparent diameter on the 1st is 15 seconds; on July 1st, 19 seconds: magnified one hundred times, she would, on the latter occasion, be as large as the Moon. With our satellite she will be in pleasing proximity on the evening of the 17th. On the 15th her distance from us will be equal to our mean distance from the Sun.

MARS will, toward the end of the month, begin to appear in the mornings a little before sunrise.

JUPITER, with a diameter more than double that of Venus, and a full disc, does not nearly equal her brilliancy. Being seven times as distant from the Sun, the light he receives from that body is fortynine times less intense: consequently, supposing that the two bodies reflect light equally, that which we should receive from a certain portion of the disc of Venus would be forty-nine times greater than

that which would reach us from an apparently equal portion of the dise of Jupiter. Thus, were the illuminated part of his disc even six times that of Venus, his light would be eight times weaker. The table shows that, toward the end of the month, he rises only a few minutes after Venus sets.

SATURN will be in conjunction with the Sun on the 10th.

On the 224, at 55 minutes past noon, the Sun will have reached Lis greatest northern declination, and the summer quarter com

MEROUS.

RISING AND SETTING OF THE SUN, POR THE PARALLELS OF THE BRITISH ISLANDS.

h.m h.m.

Rises. Sets. Rises. Sets Rises. Sets Rises. Sets. Rises. Sets. . m. h. m. t. m.

h. m. h. m.

June 13 56 8

03 46 1:350 8 8 3 40 213 50 8 133 39

8

10 3 35

8 21 322

h. m. 6. m. t.a. 8 34 3 7

July 13 54 8 133 43 8 233 31 8 353 17 8 49

6669

ད་ཀ་,。

SUN AND PLANETS AT GREENWICH.

SUN. MERCURY. TENTS, MARS. JUPITER. SATURN. U KANTS.

H. I. & J. Roche, Printers, 25, Hoxton-square, London.

THE

YOUTH'S INSTRUCTER

AND

'GUARDIAN.

JULY, 1855.

CAPTAIN COOK.

(With a Portrait.)

LIKE many other men who have risen to great eminence in the world, Captain James Cook was of very humble origin. His father, at the time of his birth, was a farmer's labourer, married to a woman of the same class. But James and Grace Cook were noted among their neighbours for honesty, sobriety, and diligence. They first lived at Morton and then at Marton, villages in the North Riding of Yorkshire. At Marton Captain Cook was born, on the 27th of October, 1728, and baptized on the 3d of November following.

The first instructress of the most famous of British navigators was one dame Walker, schoolmistress of the village; and the utmost honour he witnessed in his family was the promotion of his father to be hind, or head servant, on a farm belonging to Thomas Skottow, Esq., called Airy Holme, near Great Ayton. At the cost of Mr. Skottow, James was sent to a day-school in Ayton, where he learned as much as was then imparted to the most favoured of the common people, -writing, and a few first rules of arithmetic. When in his thirteenth year, he was bound apprentice to Mr. William Sanderson, a haberdasher in Staiths, a fishing-town about ten miles north of Whitby. Haberdashery, however, did not suit James Cook, who sighed for a sea-life; and the situation of Staiths, and the calling of those with whom he VOL. XIX. Second Series.