When Rudolph saw the magnificent instruments which Tycho had brought
along with him, and had acquired some knowledge of their use, he pressed
him to send to Denmark for the still larger ones which he had left at
Stiern-berg. In the meantime, he gave him the choice of the castles of
Brandisium, Lyssa, and Benach as his country residence; and after
visiting them about the end of May, Tycho gave the preference to Benach,
which was situated upon a rising ground, and commanded an extensive
horizon. It contained splendid and commodious buildings, and was almost,
as he calls it, a small city, situated on the stream Lisor, near its
confluence with the Albis. It stood a little to the east and north of
Prague, and was distant from that city only five German miles, or about
six hours' journey.

On the 20th of August, the Prefect of Brandisium gave Tycho possession
of his new residence. His gratitude to his royal patron was copiously
displayed, not only in a Latin poem written on the occasion, but in
Latin inscriptions which he placed above the doors of his observatory
and his laboratory. In order that he might establish an astronomical
school at Prague, he wrote to Longomontanus, Kepler, Muller, David
Fabricius, and two students at Wittemberg, who were good calculators,
requesting them to reside with him at Benach, as his assistants and
pupils: He at the same time dispatched his destined son-in-law,
Tengnagel, accompanied by Pascal Muleus, to bring home his wife and
daughters from Wandesberg, and his instruments from Huen; and he begged
that Longomontanus would accompany them to Denmark, and return in the
same carriage with them to Bohemia.

Kepler arrived at Prague in January 1600, and, after spending three or
four months at Benach, in carrying on his inquiries and in making
astronomical observations, he returned to Gratz. Tycho had undertaken to
obtain for him the appointment of his assistant. It was arranged that
the Emperor should allow him a hundred florins, on the condition that
the states of Styria would permit him to retain his salary for two
years. This scheme, however, failed, and Kepler was about to study
medicine, and offer himself for a professorship of medicine at Tubingen,
when Tycho undertook to obtain him a permanent appointment from the
Emperor. Kepler, accordingly, returned in September 1601, and, on the
recommendation of his friend, he was named imperial mathematician, on
the condition of assisting Tycho in hi