t Professor Forbes so aptly styles the geometrical period. These
three Sir David Brewster has termed "Martyrs of Science"; Galileo, the
great Italian philosopher, has his own place among the "Pioneers of
Science"; and invaluable though Tycho Brahe's work was, the latter can
hardly be claimed as a pioneer in the same sense as the other two.
Nevertheless, Kepler, the third member of the trio, could not have made
his most valuable discoveries without Tycho's observations.

Of noble family, born a twin on 14th December, 1546, at Knudstrup in
Scania (the southernmost part of Sweden, then forming part of the
kingdom of Denmark), Tycho was kidnapped a year later by a childless
uncle. This uncle brought him up as his own son, provided him at the age
of seven with a tutor, and sent him in 1559 to the University of
Copenhagen, to study for a political career by taking courses in
rhetoric and philosophy. On 21st August, 1560, however, a solar eclipse
took place, total in Portugal, and therefore of small proportions in
Denmark, and Tycho's keen interest was awakened, not so much by the
phenomenon, as by the fact that it had occurred according to prediction.
Soon afterwards he purchased an edition of Ptolemy in order to read up
the subject of astronomy, to which, and to mathematics, he devoted most
of the remainder of his three years' course at Copenhagen. His uncle
next sent him to Leipzig to study law, but he managed to continue his
astronomical researches. He obtained the Alphonsine and the new Prutenic
Tables, but soon found that the latter, though more accurate than the
former, failed to represent the true positions of the planets, and
grasped the fact that continuous observation was essential in order to
determine the true motions. He began by observing a conjunction of
Jupiter and Saturn in August, 1563, and found the Prutenic Tables
several days in error, and the Alphonsine a whole month. He provided
himself with a cross-staff for determining the angular distance between
stars or other objects, and, finding the divisions of the scale
inaccurate, constructed a table of corrections, an improvement that
seems to have been a decided innovation, the previous practice having
been to use the best available instrument and ignore its errors. About
this time war broke out between Denmark and Sweden, and Tycho returned
to his uncle, who was vice-admiral and attached to the king's suite. The
uncle died in the following month, and early i