Equation of Time. To change time, as shown by a good sun-dial, to that which should be indicated at the same moment by a well-regulated clock, it must be corrected by the quantities inserted in the following TABLE Of the Equation of Time for every fifth Day. m. s. Wednesday.. April 1st, to the time by the dial add 3 59 2 30 1 6 ..16th, from the time by the dial sub. 0 12 Monday... .......... 6th........ Saturday ..11th. Thursday Tuesday ......... ..21st...... Sunday ...26th.... ........ For any day intermediate to those in the Table, the quantity to be employed must be found by proportion. LUNAR PHENOMENA. Phases of the Moon. New Moon 3d day, at 21 m. past 10 at night Moon's Passage over the Meridian. The following passages of the Moon over the first meridian will afford opportunities for observation, if the weather prove favourable at the respective times: they will, of course, require a slight correction for any other meridian than that of the Royal Observatory. April 9th at 3 m. after 5 in the afternoon PHENOMENA PLANETARUM. This planet now resembles the full Moon; her brilliancy, however, is far less than when she is nearer the earth, though her illuminated disk is then much smaller. April 1st Illuminated part = 11-71010 Dark part..... Eclipses of Jupiter's Satellites. Only the following four eclipses of the first and second of the satellites will be visible this month: viz. Immersions. First Satellite.. 1st day, at 44 m. 43 s. after 4 in the morning 6.. 43 0 25 12 20 ...... Form of Saturn's Ring. 2 ..... ... The relative proportions of Saturn's ring, at this period, are the following. Our youthful readers should be reminded, that it is the southern side of the ring which is now visible, as indicated by the sign being prefixed to the conjugate axis. Conjunction of the Moon with the Planets and Stars. April 7th, with 18 in Taurus.. at 11 in the morning 7th .28.. Taurus 7th ... .... a.. Taurus 12th....la Cancer ....2a 12th 21st .... Cancer 6... Libra...... 4 in the morning 26th B.. Capricorn....... 7. Other Phenomena. Saturn will be in quadrature at 45 m. after 1 in the morning of the 18th; and Georgium Sidus at half past 8 in the evening of the 26th of this month. We shall insert here the following instances to show the great utility of the Marine Barometer, when its friendly admonitions are strictly regarded. As the Chronometer should be its never-failing companion, we also subjoin a striking instance of its utility to those whose business is on the bosom of great waters. -See Arnott's Elements of Physics. Barometer. To the husbandman the barometer is of considerable use, by aiding and correcting his prognostication of the weather drawn from local signs familiar to him; but its great use as a weather-glass seems to be to the mariner, who roams over the whole ocean, under skies and climates altogether new to him. The watchful captain of the present day, trusting to this extraordinary monitor, is often enabled to take in sail, and to make ready for the storm, where, in former times, the dreadful visitation would have fallen upon him unprepared. The marine barometer has not yet been in general use for many years, and the author was one of a numerous crew who probably owed their preservation to its almost miraculous warning. It was in a southern latitude. The sun had just set with placid appearance, after a beautiful afternoon, and the usual mirth of the evening watch was proceeding, when the captain's order came to prepare, with all haste, for a storm. The barometer had begun to fall with appalling rapidity. As yet the old sailors had not perceived even a threatening in the sky, and they were surprised at the extent and hurry of the preparations; but the required measures were not completed, when a more awful hurricane burst upon them than the most experienced had ever braved. Nothing could withstand it; the sails, already furled and closely bound to the yards, were riven away in tatters; even the bare yards and masts were in great part disabled; and at one time the whole rigging had nearly fallen by the board. Such, for a few hours, was the mingled roar of the hurricane above, of the waves around, and of the incessant peals of thunder, that no human voice could be heard, and, amidst the general consternation, even the trumpet sounded in vain. In that awful night, but for the little tube of mercury which had given the warning, neither the extraordinary strength of the noble ship, nor the skill and energies of the commander, would have saved one man to tell the tale. On the following morning the wind was again at rest, but the ship lay upon the yet heaving waves an unsightly wreck. Chronometer. It would be exceeding the limit marked out for this general work, to speak more particularly of those admirable watches which have been produced, within the last thirty years, under the name of chronometers, for the purpose of finding the longitude at sea; but the author may, perhaps, be excused for mentioning here a moment of surprise and delight which he experienced when he first saw their singular perfection experimentally proved. After months spent at sea, in a long passage from South America to Asia, his pocket chronometer, with others on board, announced one morning that a certain point of land was now bearing north from the ship, at a distance of only fifty miles: in an hour afterwards, when a mist had cleared away, the looker-out on the mast gave the joyous call of land a-head!' verifying the report of the chronometers almost to one mile, after a voyage of thousands. It is allowable at such a moment, with the dangers and uncertainties of ancient navigation before the mind, to exult, in contemplating what man has now achieved-in contemplating the correctness of the sciences, and the perfection of the various arts which contribute to such a result as now related. We shall now introduce to our readers the following lines, which require neither apology nor com ment: To the MOON: by JANE TAYLOR. What is it that gives thee, mild Queen of Night, Or why should I gaze with such pensive delight What gentle enchantment possesses thy beam, Thy bosom is cold as the glittering stream Canst thou the sad heart of its sorrows beguile, Yet, where is the mourner but welcomes thy smile, The tear that looks bright, in the beam, as it flows, The sorrow that loves in thy light to repose, Yet soothing thou art,-and for ever I find, A moonlight composure steal over my mind, I think of the years that for ever have fled; Of joys that are vanished-and hopes that are dead; I think of the future, still gazing the while, But ne'er dost thou grant one encouraging smile, Thy beams, which so bright through my casement appear, To far distant regions extend; Illumine the dwellings of those that are dear, And sleep on the grave of a friend. Then still must I love thee, mild Queen of the Night! Since feeling and fancy agree To make thee a source of unfailing delight, A friend and a solace to me! Watts's Poetical Album. |