tween real and apparent motion, nor the
distance of the sun and stars, nor their relative size and weight, nor
the laws of motion, nor the principles of gravitation, nor the nature
of the Milky Way, nor the existence of nebulae, nor any of the wonders
which the telescope reveals; but in the severity of their mathematical
calculations they were quite equal to modern astronomers.

If Copernicus revolutionized astronomy by proving the sun to be the
centre of motion to our planetary system, Galileo gave it an immense
impulse by his discoveries with the telescope. These did not require
such marvellous mathematical powers as made Kepler and Newton
immortal,--the equals of Ptolemy and Hipparchus in mathematical
demonstration,--but only accuracy and perseverance in observations.
Doubtless he was a great mathematician, but his fame rests on his
observations and the deductions he made from them. These were more
easily comprehended, and had an objective value which made him popular:
and for these discoveries he was indebted in a great measure to the
labors of others,--it was mechanical invention applied to the
advancement of science. The utilization of science was reserved to our
times; and it is this utilization which makes science such a handmaid to
the enrichment of its votaries, and holds it up to worship in our
laboratories and schools of technology and mines,--not merely for
itself, but also for the substantial fruit it yields.

It was when Galileo was writing treatises on the Structure of the
Universe, on Local Motion, on Sound, on Continuous Quantity, on Light,
on Colors, on the Tides, on Dialing,--subjects that also interested Lord
Bacon at the same period,--and when he was giving lectures on these
subjects with immense _eclat_, frequently to one thousand persons
(scarcely less than what Abelard enjoyed when he made fun of the more
conservative schoolmen with whom he was brought in contact), that he
heard, while on a visit to Venice, that a Dutch spectacle-maker had
invented an instrument which was said to represent distant objects
nearer than they usually appeared. This was in 1609, when he, at the age
of fifty-five, was the idol of scientific men, and was in the enjoyment
of an ample revenue, giving only sixty half-hours in the year to
lectures, and allowed time to prosecute his studies in that "sweet
solitariness" which all true scholars prize, and without which few great
attainments are made. The rumor of the inventi