r
Robertson, of Oxford, in 1822,[14] he informed me that he had examined a
portion of Harriot's papers, entitled, "De Jovialibus Planetis;" and
that it appears, from two pages of these papers, _that Harriot first
observed Jupiter's satellites on the 17th of October, 1610_. These
observations are accompanied with rough drawings of the positions of the
satellites, and rough calculations of their periodical revolutions. My
friend, Professor Rigaud,[15] who has very recently examined the Harriot
MSS., has confirmed the accuracy of Dr Robertson's observations, and has
thus restored to Galileo the honour of being the first and the sole
discoverer of these secondary planets.

[13] Berlin Ephemeris, 1788.

[14] Edin. Phil. Journ. vol. vi. p. 313.

[15] Life and Correspondence of Dr Bradley, Oxford, 1832, p. 533,
See also his Supplement. Oxford, 1833, p. 17.

CHAPTER III.

_Galileo announces his discoveries in Enigmas--Discovers the
Crescent of Venus--the Ring of Saturn--the Spots on the
Sun--Similar Observations made in England by Harriot--Claims of
Fabricius and Scheiner to the discovery of the Solar
Spots--Galileo's Letters to Velser on the claims of Scheiner--His
residence at the Villa of Salviati--Composes his work on Floating
Bodies, which involves him in new controversies._

The great success which attended the first telescopic observations of
Galileo, induced him to apply his best instruments to the other planets
of our system. The attempts which had been made to deprive him of the
honour of some of his discoveries, combined, probably, with a desire to
repeat his observations with better telescopes, led him to announce his
discoveries under the veil of an enigma, and to invite astronomers to
declare, within a given time, if they had observed any new phenomena in
the heavens.

Before the close of 1610, Galileo excited the curiosity of astronomers
by the publication of his first enigma. Kepler and others tried in vain
to decipher it; but in consequence of the Emperor Rodolph requesting a
solution of the puzzle, Galileo sent him the following clue:--

"Altissimam planetam tergeminam observavi."

I have observed that the most remote planet is triple.

In explaining more fully the nature of his observation, Galileo remarked
that Saturn was not a single star, but three together, nearly touching
one another. He described them as having no relat