Sirius. Regulus being added to the number, and Castor being doubled, we have fourteen stars, to all of which, except to Regulus, is assigned a motion. in declination, as well as in right ascension; so that we have no less than 27 motions given to account for. Now, by assuming a point somewhere near λ Hercules, and supposing the Sun to have a proper motion towards that part of the heaven, most of these are accounted for: For ẞ Cygni, a Aquila, ε Cygni, Piscium, y Arietis, and Aldebaran, ought, on the supposed motion of the Sun, to have an apparent progression, or to increase in right ascension, while Arcturus, Regulus, the two stars a Geminorum, Pollux, Procyon, Sirius, and y Geminorum, should apparently go back, so as to decrease in right ascension, which, in almost all the cases, is found to correspond with the fact. The correspondence of the theory and fact, with regard to the change of declination, is equally striking, and Dr. Herschel says the exceptions must be resolved into the real proper motion of the stars. The author of this valuable paper says, there are some very striking circumstances in the quantities of those motions that deserve notice. First, Arcturus and Sirius being the largest stars, and, therefore, probably the nearest, ought to have the most apparent motion, both in right ascension and declination, which is agreeable to observation. Secondly, in regard to right ascension only, Arcturus being better situated to show its motion, ought to have it much larger, which it has. Aldebaran, both badly situated, and considerably smaller than the two former, ought to show but little motion, which is the case. Procyon, better situated than Sirius, though not so large, should have almost as much motion; for, on the supposition that it is farther off, because it appears smaller, the effect of the Sun's motion will be lessened on it; whereas its better situation will partly. compensate for its greater distance. This also is conformable to matter of fact and the table. With respect to the quantity of motion of the solar system, Dr. Herschel says, that we may certainly admit that the diameter of the Earth's orbit, at the distance of Sirius or Arcturus, would not nearly subtend an angle of 1"; but the apparent motion of Arcturus, if owing to the motion of the solar system, amounts to 2".7 a year, as appears by compounding the two motions of right ascension and declination into one motion, and reducing it to an annual quantity; and hence he infers that the solar motion is not less than that which the Earth has in her annual orbit. [To be continued.] Astronomical Occurrences. THE Sun enters Virgo on the 23d day of August, at 5 m. past 8 o'clock in the morning. Mercury will. be in his superior conjunction on the 18th, at 17 m. past 4 in the afternoon. Saturn will be in opposition with respect to the Earth at 4 past 5 in the afternoon on the 13th; and the Herschel will be in his quadrature on the 30th, at past 12 at night: between this last named planet and the Moon there will be a near appulse at 55 m. past 5 in the afternoon of the 2d day; and, on the 16th, he is stationary. TABLE Of the Sun's Rising and Setting every fifth Day of the Month. Thursday, August 1, Sun rises 18 m. past 4 sets 42 m. past 7 Tuesday, 34 25 16 7 7 7. Equation of Time. [See January.] Aug. 1, to the time on the dial add 6, m. sec. 5257 11, 16, 21, 26, 31, The Moon is full on the 8th day of August, at 18 m. past 1 in the morning: she enters her last quarter at 58 m. past 4 in the morning on the 16th. The New Moon is on the 23d, at 6 m. past 7 in the morning; and she enters her first quarter on the 29th, at 43 m. past 9 in the evening. There are no eclipses of Jupiter's satellites visible this month. In our tables relating to these phenomena, we have sometimes noticed their immersions, and, sometimes, their emersions. The immersions. signify the instant of the disappearance of the satellite, by entering the shadow of Jupiter; and the emersions signify the first instant of its appearance at coming out of the same. They generally happen when the satellite appears at some distance from the body of Jupiter, except near the opposition of Jupiter to the Sun, when the satellite approaches nearer to his body. Before the opposition of Jupiter, the immersions and emersions happen on the west side of Jupiter; and, after opposition, on the east side; but if an astronomical telescope be used, which reverses the appearance of objects, the appearance will be directly contrary to this. Before the opposition, the immersions only of the first satellite are visible; and, after the opposition, the emersions only. The same is generally the case with respect to the second satellite: both immersion and emersion are frequently observable in the two outer satellites. In the Nautical Almanack, and also in other Ephemerides, the immersions and emersions, which are marked with an asterisk, are those that are visible at Greenwich. To know if an eclipse will be visible in any place, find whether Jupiter be 8° above the horizon of that place, and the Sun as much below. This may be done by means of the celestial globe. The immersion or emersion of any satellite being carefully observed in any place, according to mean time, the longitude from Greenwich is found immediately, by taking the difference of the observation from the corresponding time shown in the Nautical Almanack or Ephemeris, which must be turned into degrees; and it will be east or west of Greenwich, as the time observed is more or less than that of the Ephemeris. Example. Suppose, on the 2d of January, 1816, the time of the immersion of Jupiter's first satellite be observed by a telescope, in an unknown meridian, to happen at 18h 20m 55s; I find, by the table in the Ephemeris, that it will happen at the Observatory, at Greenwich, at 16h 32m 33s: the difference of time is 1h 48m 20, which, being converted into degrees and minutes of the equator (since 15° is equal to 1 hour in time), gives 27° 5', equal the longitude of the place east, because the time is more than that at Greenwich. According to our table [see January] the time will be found 32 m. after 4 in the morning of the 3d day, which answers to 32 m. after 16, astronomical time. The Naturalist's Diary. Now jocund Summer, with her honied breath, Beneath her hat of straw. THE month of August is, usually, the finest and most settled in the whole year. Fine weather, in deed, is very desirable in this month, that the principal, source of the farmer's wealth may be safely housed; for sudden storms beat down the nearly ripe corn, and materially injure it. The time of commencing the harvest varies greatly in different districts. It is usually begun in the southern and midland parts of the kingdom towards the end of July, but principally at the beginning of this month; in the northern districts of Scotland, the harvest does not commence until the first or second week in September; and it is but rarely that, in these parts of England, it is finished, even in the most favourable situations, before the end of October; and not unfrequently this time is protracted till the middle of November. For the various modes of gathering the harvest, see T. T. for 1814, p. 213. Mr. White has given us a most pleasing description of a Harvest Scene,' in the poems appended to his excellent Natural History of Selborne, vol. ii, p. 343. Waked by the gentle gleamings of the morn, But when high noon invites to short repast, About the 11th of August, the puffin (alca arctica) migrates. Priestholme, or Puffin's Island, about |