By Prof. M. B. GOFF.
FOR JULY.
THE SUN.
We now enter upon what is usually called the “heated term,” in earnest. The “Dog Days” are upon us, that is, we say they are; but the statement is a somewhat doubtful one. We have the story that the ancients regarded the Dog Star, Sirius, in the constellation Canis Major, as the source of “unnumbered woes,” because it rose a short time before the sun about the season of their year that the hot weather set in, and diseases incident to their climate more than usually prevailed. It is said that they estimated this period as continuing for the space of forty consecutive days, beginning twenty days before, and continuing twenty days after what was called the heliacal (that is, rising just long enough before the sun to be visible) rising of the Dog Star. Now, the difficulty we moderns find in fixing the limits of these days is this: The heliacal rising of the star for any one place can readily be found; but when determined for one place, it would not suit for another in a different latitude. Besides, the right ascension of Sirius, on account of the precession of the equinoxes, is constantly increasing, and hence for the same place these days fall later each year, in the course of time occurring even in mid-winter. Almanac makers, when they notice them at all, seem to take the liberty of treating them to suit their own convenience. For example, one of this year’s publications announces that “Dog Days” begin on the 21st of July, and end on the 30th of August, making, as we see by including one extreme date, altogether the forty days claimed by the ancients. But in this latitude, on the former date, the star rises at 5:43 a. m., one hour and five minutes after, and on the latter date at 3:06 a. m., two hours and twenty minutes before sunrise. Others fix the time from July 3rd to August 11th (forty days), without any respect to the rising of Sirius, which on the former date appears above our horizon at 6:51 a. m., or two hours and seventeen minutes after, and on the latter date at 4:18 a. m., forty-nine minutes before sunrise. Others, again, making an effort, we presume, to adapt them to our climate, regard them as continuing only thirty-two days, namely, from July 24th to August 24th. Taking it all in all, we may as well leave them to the Egyptians and Ethiopians, among whom the ideas in regard to them seem to have originated, as a superstition of the past ages, taking our “heated term” at its usual time, July and August, and throwing our “Dog Days,” as some do physic, “to the dogs.”
Whether we account for it by the extreme heat or not, it is nevertheless a fact that the sun lags along behind our clocks during this entire month; on the 1st, not reaching the meridian till 12:03:41 p. m.; on the 15th till 12:05:44 p. m., and on the 30th till six minutes and nine seconds after noon. The time of the sun’s rising on the 1st, 15th and 30th, is 4:33, 4:43 and 4:56 a. m.; and the time of setting on the same dates is 7:34, 7:29 and 7:17 p. m., respectively. The 30th day of this month will be about forty minutes shorter than the 1st, the latter being fifteen hours one minute, and the former fourteen hours and twenty-one minutes in length. The time from daybreak to the end of twilight is, on the 1st, 19 hours 24 minutes. Sun is due west on the 30th at 5:29 p. m. Its greatest elevation above the horizon in latitude 41° 30′, is 71° 33⅔′.
THE MOON
Exhibits the following phases: Full moon, 5:02 a. m. on the 8th; last quarter, 4:30 p. m. on the 15th; new moon, 7:46 a. m. on the 22nd; first quarter on the 29th, at 4:53 p. m. On the 1st it sets at 12:11 a. m., and on the 30th, at 11:51 p. m. On the 15th, rises at 11:32 p. m. On the 4th, at 7:54 a. m., and again on the 31st at 11:00 p. m. it is at its maximum distance from the earth. On the 20th, at 1:36 a. m. is nearest the earth. Its greatest elevation, equal 67° 13⅔′, occurs on the 19th; and its least elevation, amounting to 29° 42⅔′ on the 5th.