Location.—One corner of the Great Square is found by drawing a line from Polaris to Cassiopeia, and prolonging it an equal distance.
The Great Square is a stellar landmark. Three of the corners of the square are marked by stars in Pegasus; the fourth, and northeastern, corner is marked by the star Alpheratz in Andromeda. Each side of the square is about 18° long.
The horse is generally seen upside down, with his fore feet projected up int
π is an interesting double, easily seen in an opera-glass. All the stars of the Square are approaching us at an inconceivable speed.
The position of the asterism Equus or Equūleus, the Little Horse, or Horse's Head, is shown in the diagram.
Delphinus, the water jar of Aquarius, and the circlet in the Western Fish, are all in the vicinity of Pegasus, and indicated in the diagram.
The winged horse is found on coins of Corinth 500 to 430 b.c. The Greeks called this constellation ἱπποσ.
Pegasus seems to have been regarded in Phœnicia and Egypt as the sky emblem of a ship.
Within the area of the Square Argelander counted thirty naked-eye stars.
Note a fine pair in Equūleus just west of the star Enif in Pegasus.
The position of the equinoctial colure is defined by a line connecting Polaris, β Cassiopeiæ, α Andromedæ, and γ Pegasi.