es reappeared; but Galileo's glass was not sufficiently
powerful to enable him to ascertain their nature nor solve the mystery,
which for upwards of half a century perplexed the ablest astronomers.

The elucidation of this inexplicable phenomenon was reserved for
Christian Huygens, who, with an improved telescope of his own
construction, was able to declare that Saturn's appendages were portions
of a ring which surrounds the planet, and is everywhere distinct from
its surface.

Galileo next directed his attention to the planet Venus, and as a result
of his observations was led to communicate to the public another
anagram:--

Haec immatura a me jam frustra leguntur oy.

This, when rendered correctly, reads:--

Cynthiae figuras aemulatur mater amorum.

Venus rivals the appearances of the Moon.

The phases of Venus were one of the most interesting of Galileo's
discoveries with the telescope. When observed near inferior conjunction
the planet presents the appearance of a slender crescent, resembling
the Moon when a few days old. Travelling from this point to superior
conjunction, the illumined portion of her disc gradually increases,
until it becomes circular, like the full Moon. This changing appearance
of Venus afforded Galileo irresistible proof that the planet is an
opaque body, which derives its light from the Sun, and that it circles
round the orb--convincing evidence of the accuracy and truthfulness of
the Copernican theory.

It was in this manner that Galileo announced his discovery of the phases
of Venus, the peerless planet of our morning and evening skies, whose
slender crescent forms such a beautiful object in the telescope, and
who, as she traverses her orbit, exhibits all the varied changes of form
presented by the Moon in her monthly journey round the Earth. These
varying aspects of Venus were not unknown to Milton; and, indeed, he may
have been informed of them by Galileo in his conversation with him at
Arcetri; nor has he failed to introduce an allusion to this beautiful
phenomenon in his poem. In his description of the Creation, after the
Sun was formed, he adds:--

Hither, as to their fountain, other stars
Repairing, in their golden urns draw light,
And hence the morning planet gilds her horns.--vii. 364-66.

Galileo also discovered that the planet Mars does not always present the
appearance of a circular disc. When near opposition the full disc of the
planet is visibl