this continent, let us hope it shall be found to have been
as one of the results of societies like this, striving to make more
popular the study of astronomy.

It is not by any means proposed to inflict upon you a history of the
telescope, but your indulgence is asked for a few moments while
reference is made to one or two matters connected with its invention,
or, rather, its accidental discovery and subsequent improvement.

The opening years of the seventeenth century found the world without a
telescope, or, at least, such an instrument as was adapted for
astronomical work. It is true that long years before, Arabian and some
other eastern astronomers, for the purpose, possibly, of enabling them
to concentrate their gaze upon celestial objects and follow their
motions, had been accustomed to use a kind of tube consisting of a
long cylinder without glasses of any kind and open at both ends. For
magnifying purposes, this tube was of no value. Still, it must have
been of some kind of service, or else the first telescopes, as
constructed by the spectacle makers, who had stumbled upon the
principle involved, were exceedingly sorry affairs, for, soon after
their introduction, the illustrious Kepler, in his work on "Optics,"
recommended the employment of plain apertures, without lenses, because
they were superior to the telescope on account of their freedom from
refraction.

But as soon as the principle by which distant objects could,
apparently, be brought nearer the eye became known and its value
recognized by philosophers, telescopes ceased to be regarded as toys,
and underwent material improvements in the hands of such men as
Galilei, and, later, even of Kepler himself, Cassini, Huyghens, and
others. Galilei's first telescope magnified but three times, and his
best not much above thirty times. If I comprehend aright what has been
written upon the subject, I am justified in saying that this little
instrument in my hand, with an aperture of one inch and one-quarter,
and a focus, with an astronomical eye-piece, of about ten inches, is a
better magnifier than was Galilei's best. With it I can see the moons
of Jupiter, some spots on the sun, the phases of Venus, the
composition, in some places, of the Milky Way, the seas, the valleys,
the mountains, and, when in bold relief upon the terminator, even some
of the craters and cones of the moon. Indeed, I am of opinion I can
see even more than he could, for I can readily make o