_Eridanus_, the River; 4, _Lepus_, the Hare; 5,
_Canis Major_, the Great Dog; 6, _Canis Minor_, the Little Dog; 7,
_Argo_, the Ship and Rock; 8, _Hydra_, the Water-snake; 9, _Crater_, the
Cup; 10, _Corvus_, the Raven; 11, _Centaurus_, the Centaur; 12,
_Lupus_, the Beast; 13, _Ara_, the Altar; 14, _Corona Australis_, the
Southern Crown; 15, _Piscis Australis_, the Southern Fish.

Aratus, living four hundred years earlier than Ptolemy, differs only
from him in that he reckons the cluster of the Pleiades--counted by
Ptolemy in Taurus--as a separate constellation, but he has no
constellation of _Equuleus_. The total number of constellations was thus
still forty-eight. Aratus further describes the Southern Crown, but
gives it no name; and in the constellation of the Little Dog he only
mentions one star, _Procyon_, the Dog's Forerunner. He also mentions
that the two Bears were also known as two Wagons or Chariots.

Were these constellations, so familiar to us to-day, known before the
time of Aratus, and if so, by whom were they devised, and when and
where?

They were certainly known before the time of Aratus, for his poem was
confessedly a versification of an account of them written by Eudoxus
more than a hundred years previous. At a yet earlier date, Panyasis,
uncle to the great historian Herodotus, incidentally discusses the name
of one of the constellations, which must therefore have been known to
him. Earlier still, Hesiod, in the second book of his _Works and Days_,
refers to several:--

"Orion and the Dog, each other nigh,
Together mounted to the midnight sky,
When in the rosy morn Arcturus shines,
Then pluck the clusters from the parent vines.

* * * * *

Next in the round do not to plough forget
When the Seven Virgins and Orion set."

Much the same constellations are referred to by Homer. Thus, in the
fifth book of the _Odyssey_,--

"And now, rejoicing in the prosperous gales,
With beating heart Ulysses spreads his sails:
Placed at the helm he sate, and marked the skies,
Nor closed in sleep his ever-watchful eyes.
There view'd the Pleiads and the Northern Team,
And great Orion's more refulgent beam,
To which around the axle of the sky
The Bear, revolving, points his golden eye."

Thus it is clear that several of the constellations were perfectly
familiar to the Greeks a thousand years bef