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′.