Hence, also, in the present day we hear sailors speak of the full and change, or the quartering of the moon, in connection with a gale at sea; thus showing, at least, their faith in the influence of the phenomenon. Yet it is actually the case, at certain times, that in about latitude 40° and 41°, the storms appear about a week apart. There is some reason, also, to suspect, that there is a difference of temperature on opposite sides of the sun. As the synodical rotation is nearly identical with the siderent period of the moon, this would require about forty-four years to run its course, so as to bring the phenomena to exact coincidence again. Since these observations were made, it is understood that Sig. Secchi has determined that the equatorial regions of the sun are hotter than his polar regions. It may be owing to this fact, that we have inferred a necessity for a change, whose period is a multiple of the sun's synodical rotation, but it is worthy of examination by those who possess the necessary conveniences. Another period which must influence the character of different years, depends on the conjunction of the perigee of the lunar orbit with the node. Taking the mean direct motion of the moon's perigee, and the mean retrograde motion of the node, we find that it takes six years and one day nearly from conjunction to conjunction. Now, from the principles laid down, it follows, that when the perigee of the orbit is due north, and the ascending node in Aries, that the vortices of the earth will attain their greatest north latitude; and when these conditions are reversed, the vortices will reach their highest limit in the lowest latitude. This will materially affect the temperature of the polar regions. In the following table, we have calculated the times of the conjunctions of the apogee and pole of the orbit, taking the mean motions. It may be convenient to refer to by-and-bye, remembering that when the conjunction takes place due south, the vortices reach the highest, but when due north, the vortices in the northern hemisphere have their lowest upper limit: CONJUNCTION OF APOGEE AND POLE OF ORBIT.[24] Year. Month and Day. Longitude. 1804, April 18th, 220° 1810, " 17th, 104 1816, " 16th, 348° 1822, " 15th, 232 1828, " 14th, 116 1834, " 12th, 360 1840, " 11th, 244 1846, " 10th, 128 1852, " 9th, 12 1858, " 8th, 255 1864, " 7th, 139 1870, " 6th, 23 1876, " 5th, 267 By this we see that the vortices have never attained their highest limit during the present century, but that in 1858 their range will be in a tolerable high latitude, and still higher in 1876--neglecting the eccentricity of the orbit.