ouble
stars, etc., owe their detection to small instruments; that our
knowledge of sun spots, lunar and planetary features is also very
largely derived from similar sources; that there is no department
which is not indebted to the services of small telescopes, and that of
some thousands of drawings of celestial objects, made by observers
employing instruments from three to seventy-two inches in diameter, a
careful inspection shows that the smaller instruments have not been
outdone in this interesting field of observation, owing to their
excellent defining powers and the facility with which they are used."
Aperture for aperture, the record is more glorious for the "common
telescope" than for its great rivals. Let us for a moment recall
something of what has been done with instruments which may be embraced
under the designation "common" as such a statement may serve to remove
impressions that small telescopes are but of little use in
astronomical work.

In his unrivaled book, Webb declares that his observations were
chiefly made with a telescope five and one-half feet long, carrying an
object glass of a diameter of three and seven-tenths inches. The
instrument was of "fair defining quality," and one has but to read his
delightful pages in order to form an idea of the countless pleasures
Webb derived from observation with it. Speaking of it, he says that
smaller ones will, of course, do less, especially with faint objects,
but are often very perfect and distinct, and that even diminutive
glasses, if good, will, at least, show something never seen without
them. He adds: "I have a little hand telescope twenty-two and
one-quarter inches long, when fully drawn out, with a focus of about
fourteen inches, and one and one-third inches aperture; this, with an
astronomical eye-piece, will show the _existence_ of sun spots, the
mountains in the moon, Jupiter's satellites and Saturn's ring." In
another place, speaking of the sun, he says that an object glass of
only two inches will exhibit a curdled or marbled appearance over the
whole solar disk, caused by the intermixture of spaces of different
brightness. And I may add here that Dawes recommends a small aperture
for sun work, including spectroscopic examinations, he himself, like
Mr. Miller, our librarian, preferring to use for that purpose a four
inch refractor.

As you know, the North Star is a most beautiful double. Its companion
is of the ninth order of magnitude, that is,