ame to the
conclusion that the selling of woollen stuffs would hardly satisfy his
aspirations for long, and that it was worth a sacrifice to send him to
the University. So to the University of his native town he went, with
the avowed object of studying medicine, that career seeming the most
likely to be profitable. Old Vincenzo's horror of mathematics or science
as a means of obtaining a livelihood is justified by the fact that while
the University Professor of Medicine received 2,000 scudi a year, the
Professor of Mathematics had only 60, that is L13 a year, or 7-1/2_d._ a
day.

So the son had been kept properly ignorant of such poverty-stricken
subjects, and to study medicine he went.

But his natural bent showed itself even here. For praying one day in the
Cathedral, like a good Catholic as he was all his life, his attention
was arrested by the great lamp which, after lighting it, the verger had
left swinging to and fro. Galileo proceeded to time its swings by the
only watch he possessed--viz., his own pulse. He noticed that the time
of swing remained as near as he could tell the same, notwithstanding the
fact that the swings were getting smaller and smaller.

By subsequent experiment he verified the law, and the isochronism of the
pendulum was discovered. An immensely important practical discovery
this, for upon it all modern clocks are based; and Huyghens soon applied
it to the astronomical clock, which up to that time had been a crude and
quite untrustworthy instrument.

The best clock which Tycho Brahe could get for his observatory was
inferior to one that may now be purchased for a few shillings; and this
change is owing to the discovery of the pendulum by Galileo. Not that he
applied it to clocks; he was not thinking of astronomy, he was thinking
of medicine, and wanted to count people's pulses. The pendulum served;
and "pulsilogies," as they were called, were thus introduced to and used
by medical practitioners.

The Tuscan Court came to Pisa for the summer months, for it was then a
seaside place, and among the suite was Ostillio Ricci, a distinguished
mathematician and old friend of the Galileo family. The youth visited
him, and one day, it is said, heard a lesson in Euclid being given by
Ricci to the pages while he stood outside the door entranced. Anyhow he
implored Ricci to help him into some knowledge of mathematics, and the
old man willingly consented. So he mastered Euclid and passed on to
Archime