Note the structure of this verse:—

A | The seven stars,
B | Orion,
A | The twelve signs,
B | Arcturus.

Besides this monthly difference, there is an annual difference; for at the end of twelve months the sun does not come back to exactly the same point in the sign which commenced the year, but is a little behind it. But this difference, though it occurs every year, is so small that it will take 25,579 years for the sun to complete this vast cycle, which is called The precession of the Equinoxes; i.e., about one degree in every 71 years. If the sun came back to the precise point at which it began the year, each sign would correspond, always and regularly, exactly with a particular month; but, owing to this constant regression, the sun (while it goes through the whole twelve signs every year) commences the year in one sign for only about 2,131 years. In point of fact, since the Creation the commencement of the year has changed to the extent of nearly three of the signs. When Virgil sings—

“The White Bull with golden horns opens the year,”

he does not record what took place in his own day. This is another proof of the antiquity of these signs.

The Ecliptic, or path of the sun, if it could be viewed from immediately beneath the Polar Star, would form a complete and perfect circle, would be concentric with the Equator, and all the stars and the sun would appear to move in this circle, never rising or setting. To a person north or south of the Equator the stars therefore rise and set obliquely; while to a person on the Equator they rise and set perpendicularly, each star being twelve hours above and twelve below the horizon.

The points where the two circles (the Ecliptic and the Equator) intersect each other are called the Equinoctial points. It is the movement of these points (which are now moving from Aries to Pisces) which gives rise to the term, “the precession of the Equinoxes.”

Aratus calls him Arctophylax, i.e., the guardian of Arctos, the flock of the greater fold, called to-day the Great Bear:—

“Behind, and seeming to urge on the Bear,
Arctophylax, on earth Boötes named,
Sheds o'er the Arctic car his silver light.”

By some moderns he is mistakenly called The Waggoner. Hence the allusion of Thompson:—