Friedland--He removes to Sagan, in Silesia--Is appointed
Professor of Mathematics at Rostoch--Goes to Ratisbon to receive
his Arrears--His Death, Funeral, and Epitaph--Monument Erected to
his Memory in 1803--His Family--His Posthumous Volume, entitled
"The Dream, or Lunar Astronomy."_

Kepler was kept in a state of constant anxiety from the delay in the
Government to pay up the arrears of his pension, while their repeated
promises prevented him from accepting of other employments. He had hoped
that the affair of the Bolognese chair would rouse the imperial treasury
to a sense of its duty, and enable him to publish the Rudolphine
Tables,--that great work which he owed to the memory both of Tycho and
of Rudolph. But though he was disappointed in this expectation, an event
now occurred which at least held out the prospect of a favourable change
in his circumstances. The Emperor Mathias died in 1619, and was
succeeded by Ferdinand III., who not only continued him in the situation
of his principal mathematician, with his former pension, but promised to
pay up the arrears of it, and to furnish the means for publishing the
Rudolphine Tables.

The year 1619, so favourable to Kepler's prospects in life, was
distinguished also by the publication, at Linz, of one of his most
remarkable productions, entitled "The Harmonies of the World." It is
dedicated to James I. of England, and will be for ever memorable in the
history of science, as containing the celebrated law that the squares of
the periodic times of the planets are to one another as the cubes of
their distances. This singular volume, which is marked with all the
peculiarities which distinguish his Cosmographical Mystery, is divided
into five books. The two first books are principally geometrical, and
relate to regular polygons inscribed in a circle; the third book is a
treatise on music, in which musical proportions are derived from
figures; the fourth book is astrological, and treats of the harmony of
rays emanating on the earth from the heavenly bodies, and on their
influence over the sublunary or human soul; the fifth book is
astronomical and metaphysical, and treats of the exquisite harmonies of
the celestial motions, and of the celebrated third law of the universe,
which we have already referred to.

This law, as he himself informs us, first entered his mind on the 8th
March 1618; but, having made an erroneous calculation, he was obliged to
rej