greater help, I would blush that
any one should be able to do more than I, always remembering that word
of Virgil's--

Totidem nobis animaeque manusque.

Having heard much praise bestowed upon the works of Lansberg, a Flemish
astronomer, Horrox thought it would be to his advantage to procure a
copy of his writings. This he succeeded in obtaining after some
difficulty, and devoted a considerable time to calculating Ephemerides,
based upon the Lansberg Tables, but after making a number of
computations he discovered that they were unreliable and inaccurate.

In the year 1636 Horrox made the acquaintance of William Crabtree, a
devoted astronomer, who lived at Broughton, a suburb of Manchester. A
close friendship soon existed between the two men, and they carried on
an active correspondence about matters relating to the science which
they both loved so well.

Crabtree, who was an unbeliever in Lansberg, urged Horrox to discard the
Flemish astronomer's works, and devote his talents to the study of Tycho
Brahe and Kepler. This advice led Horrox to make a more rigorous
examination of the Lansberg Tables, and after comparing them with the
observations made by Crabtree, which coincided with his own, he resolved
to renounce them. Acting on the advice of his friend, Horrox directed
his attention to the writings of Kepler. The youthful astronomer soon
realised their value, and was charmed with the accuracy of observation
and inductive reasoning displayed in the elucidation of those general
laws which constituted a new era in the history of astronomy.

The Rudolphine Tables, which were the astronomical calculations
commenced by Tycho Brahe, and completed by Kepler, were regarded by
Horrox as much superior to those of Lansberg; but it occurred to him
that they might be improved by changing some of the numbers, and yet
retaining the hypotheses. To this task he applied himself with much
earnestness and assiduity, and after close application and laborious
study he accomplished the arduous undertaking of bringing those tables
to a high state of perfection.

In his investigation of the Lunar theory, Horrox outstripped all his
predecessors, and Sir Isaac Newton distinctly affirms he was the first
to discover that the Moon's motion round the Earth is in the form of an
ellipse with the centre in the lower focus. Besides having made this
discovery, Horrox was able to explain the causes of the inequalities of
the Moon's motion, whic