o supersede the obsolete Alphonsine Tables of the
thirteenth century.

In comparison with the question of the motion of the earth, no other
astronomical detail of the time seems to be of much consequence. Comets,
such as from time to time appeared, bright enough for naked eye
observation, were still regarded as atmospheric phenomena, and their
principal interest, as well as that of eclipses and planetary
conjunctions, was in relation to astrology. Reform, however, was
obviously in the air. The doctrine of Copernicus was destined very soon
to divide others besides the Lutheran leaders. The leaven of inquiry was
working, and not long after the death of Copernicus real advances were
to come, first in the accuracy of observations, and, as a necessary
result of these, in the planetary theory itself.

CHAPTER II.

EARLY LIFE OF KEPLER.

On 21st December, 1571, at Weil in the Duchy of Wurtemberg, was born a
weak and sickly seven-months' child, to whom his parents Henry and
Catherine Kepler gave the name of John. Henry Kepler was a petty officer
in the service of the reigning Duke, and in 1576 joined the army serving
in the Netherlands. His wife followed him, leaving her young son in his
grandfather's care at Leonberg, where he barely recovered from a severe
attack of smallpox. It was from this place that John derived the
Latinised name of Leonmontanus, in accordance with the common practice
of the time, but he was not known by it to any great extent. He was sent
to school in 1577, but in the following year his father returned to
Germany, almost ruined by the absconding of an acquaintance for whom he
had become surety. Henry Kepler was obliged to sell his house and most
of his belongings, and to keep a tavern at Elmendingen, withdrawing his
son from school to help him with the rough work. In 1583 young Kepler
was sent to the school at Elmendingen, and in 1584 had another narrow
escape from death by a violent illness. In 1586 he was sent, at the
charges of the Duke, to the monastic school of Maulbronn; from whence,
in accordance with the school regulations, he passed at the end of his
first year the examination for the bachelor's degree at Tuebingen,
returning for two more years as a "veteran" to Maulbronn before being
admitted as a resident student at Tuebingen. The three years thus spent
at Maulbronn were marked by recurrences of several of the diseases from
which he had suffered in childhood, and also by famil