GEOGRAPHY OF THE HEAVENS FOR JUNE.
Reading edition
BY PROF. M. B. GOFF, Western University of Pennsylvania.
THE SUN.
“’Tis by thy secret, strong attractive force, As with a chain indissoluble bound, Thy system rolls entire; from the far bourne Of utmost Saturn, wheeling wide his round Of thirty years, to Mercury, whose disk Can scarce be caught by philosophic eye, Lost in the near effulgence of thy blaze.”
Had our poet written his Summer in 1781, the year in which Uranus was discovered, instead of 1727; or could he have waited till 1846, his “utmost Saturn wheeling wide his round of thirty years” would probably have been changed and in beautifully flowing verse would have been expressed the wonderful fact of “utmost Neptune, wheeling wide his round, whose years could only be by four and sixty and one hundred told.” So much in one respect had astronomy grown in a little more than a century. But we could have no heart to blame our poet’s neglect of our “utmost” planets, even had he known of their existence, since he was so evidently in earnest in giving its due to our glorious orb, recognized to-day as the source of all our light, and heat, and life.
“From brightening fields of ether fair disclosed, Child of the Sun, refulgent Summer comes, In pride of youth, and felt through Nature’s depth; He comes, attended by the Hours And ever-fanning Breezes, on his way; While from his ardent look, the turning Spring Averts her blushful face; and earth and skies, All-smiling, to his hot dominion leaves. … “When now, no more the alternate Twins are fired, And Cancer reddens with the Solar blaze, Short is the doubtful empire of the Night; And soon, observant of approaching Day, The meek-eyed Morn appears, mother of Dews, At first faint-gleaming in the dappled East; Till far o’er Ether spreads the widening glow; And, from before the luster of her face, White break the clouds away.”
Had our poetic friend, Thompson, lived in Meadville or New York, instead of London, he would not even on the 21st of June, have been so much disposed to sing:
“Short is the doubtful empire of the Night;”
for the shortest night of New York is over an hour longer than the shortest night of London. But what were Meadville and New York in 1727? June 21st is our longest day, in latitude 41° 30′, a little more than fifteen hours from sunrise to sunset; the night, of course, a little less than nine hours. On this day the sun reaches his northern limit, 23° 27′ 3.2″, and at 2:42 a. m. begins his southern journey; or, to put it astronomically, the sun enters Gemini, and summer begins, on June 21st, at 1:42 a. m. On the 1st, sun rises at 4:31 a. m., sets at 7:24 p. m.; on the 16th, rises at 4:29 a. m., sets at 7:32 p. m.; and on the 30th rises at 4:33 a. m., sets at 7:34 p. m. Many persons judging from the temperature will be inclined to think on the 21st that the sun must be at midday directly above their head; but it will have an elevation of not more than 73°.
THE MOON
Enters upon its last quarter on the 5th, at 6:56 p. m.; new moon on the 12th, at 5:34 p. m.; first quarter, 19th, at 8:40 a. m.; and full on the 27th, at 6:09 a. m. Farthest from the earth on the 28th, at 12:54 a. m.; nearest the earth on the 13th, at 11:12 a. m. Greatest elevation, 66° 56′ 25″, on the 13th; least elevation, 30° 2′ 40″, on the 27th. Rises on the 1st, at 10:15 p. m.; sets on the 16th, at 10:41 p. m.; and rises on the 30th, at 9:27 p. m.
MERCURY
Will be our morning star till the 27th, after which it will be evening star till the end of the month. On the 1st it will rise at 3:34 a. m., or about one hour earlier than the sun, and can probably be seen by good eyes. On the 16th, it will rise at 3:46 a. m.; and on the 30th, will set at 7:51 p. m., or a few minutes after sunset, but will be too near the sun to be visible. Its motion will be direct, amounting to 59° 50′. Its diameter will decrease from 7″ to 5″. On the 5th, at 2:00 p. m., will be 48′ south of Neptune; on the 11th, at 10:57 a. m., 2° 57′ north of the moon; on the 23d, at 11:00 p. m., 1° 41′ north of Saturn; on the 24th, at 3:00 a. m., in perihelion (nearest the sun); and on the 27th, at 10:00 a. m., in superior conjunction with the sun.
VENUS,
Although she acts the part of an evening star, is rather “mild” this month. She rises after the sun, and sets on the 1st, at 7:56; on the 16th, at 8:20; and on the 30th, at 8:33 p. m. Her diameter increases four tenths of a second of arc; and she makes a direct motion of 40° 3′. On the 7th, at 5:00 p. m., she is 1° 32′ north of Saturn; on the 13th, at 10:54 a. m., 5° 48′ north of the moon; and on the 26th, at 3:00 p. m., in perihelion.
MARS
Has a direct motion of 22° 6′; his diameter remains constant, 4.4″, during the month. Can be seen at the early dawn. He rises at the following times: On the 1st, at 3:22; on the 16th, at 2:59; and on the 30th, at 2:33 a. m. On the 10th, at 6:00 p. m., 1° 29′ north of Neptune; on the 10th, at 7:55 p. m., 3° 51′ north of the moon.
JUPITER
“Speaks for himself” every evening this month. On the 1st, he rises at 10:34 a. m., and on the 2d sets at 12:06 a. m.; on the 16th, rises at 9:50 a. m., and sets at 11:16 p. m.; and on the 30th, rises at 9:03 a. m., and sets at 10:23 p. m. He has a direct motion of 4° 2′ 31″; and his diameter decreases from 34″ to 31.6″. On the 17th, at 9:44 a. m., he is 3° 44′ north of the moon. It may interest the general reader to know that while he is admiring, night after night, this beautiful body making its way through the “lesser lights” of the heavens, that the astronomer is laboring diligently to discover its properties and learn with exactness its motions. From the last report of Prof. G. W. Hough, Director of the Dearborn Observatory, Chicago, we find that “the disk of Jupiter was observed on every favorable occasion, and micrometric measures made on the principal spots and markings, including the great red spot first remarked in 1878.” These observations were made principally with a view to obtaining the time of revolution of the planet on its axis; and the result of the observations from September 12, 1883, to June 11, 1884, a period during which the planet made 660 revolutions, was a mean of 9h. 55m. 38.5s., which differs from the mean of five years’ observation by 1.5s.; the former mean being that much greater than the latter.
SATURN
Will be evening star till the 18th; after which date, morning star till the end of the month. On the 1st, rises at 5:40 a. m., and sets at 8:24 p. m.; on the 16th, rises at 4:47 a. m., sets at 7:31 p. m.; on the 30th, rises at 4:00 a. m., sets at 6:44 p. m.; from which it will be seen that except during the first part of the month it will be invisible to the naked eye. Its diameter is 15.6″ and does not change to the amount of one tenth of a second during the month. On the 7th, at 5:00 p. m., 1° 32′ south of Venus; on the 13th, at 1:19 a. m., 4° 3′ north of the moon; on the 18th, at 6:00 p. m., is in conjunction with the sun; on the 23d, at 11:00 p. m., 1° 41′ south of Mercury. This planet has also been the subject of observation from the Dearborn Observatory, for the purpose of detecting markings on the rings; but “nothing indicating a division in the outer ring has ever been noticed.”
URANUS.
On the 1st, this planet rises at 1:10 p. m.; on the 2nd, it sets at 1:18 a. m.; on the 16th, rises at 12:12 p. m., and on the 17th, sets at 12:18 a. m.; on the 30th, rises at 11:18 a. m., and sets at 11:24 p. m. Decreases in diameter two tenths of a second; and has a direct motion of 14″ 30′. On the 5th, at 1.00 p. m., it appears stationary; on the 19th, at 10:15 a. m., is 55′ north of the moon; on same date, at 10:00 p. m., is 90° east of the sun.
NEPTUNE
Is a morning star throughout the month, and has a direct motion of 1° 0′ 16″. Diameter increases from 2.5″ to 2.6″. It rises as follows: On the 1st, at 3:47; on the 16th, at 2:49; and on the 30th, at 1:56 a. m. On the 5th, at 2:00 p. m., is 48′ north of Mercury; on the 10th, at 6:00 p. m., 1° 29′ south of Mars; on the 10th, at 7:49 p. m., 2° 21′ north of the moon. The 26-inch equatorial of the National Observatory at Washington, D. C., was during the past year chiefly employed in observations of the satellites of Neptune, Uranus, Saturn and Mars.