e more we
study them, the more we must admire them. It is with great men, as it is
with great movements in the arts, we cannot understand them without
studying them under various points of view.

Let us here again make a general reflection. The memoirs of Herschel
are, for the greater part, pure and simple extracts from his
inexhaustible journals of observations at Slough, accompanied by a few
remarks. Such a table would not suit historical details. In these
respects the author has left almost every thing to his biographers to do
for him. And they must impose on themselves the task of assigning to the
great astronomer's predecessors the portion that legitimately belongs to
them, out of the mass of discoveries, which the public (we must say) has
got into an erroneous habit of referring too exclusively to Herschel.

At one time I thought of adding a note to the analysis of each of the
illustrious observer's memoirs, containing a detailed indication of the
improvements or corrections that the progressive march of science has
brought on. But in order to avoid an exorbitant length in this
biography, I have been obliged to give up my project. In general I shall
content myself with pointing out what belongs to Herschel, referring to
my _Treatise on Popular Astronomy_ for the historical details. The life
of Herschel had the rare advantage of forming an epoch in an extensive
branch of astronomy; it would require us almost to write a special
treatise on astronomy, to show thoroughly the importance of all the
researches that are due to him.

FOOTNOTE:

[17] These titles are copied direct from the Philosophical
Transactions, instead of being retranslated.--_Translator's
Note_.

IMPROVEMENTS IN THE MEANS OF OBSERVATION.

The improvements that Herschel made in the construction and management
of telescopes have contributed so directly to the discoveries with which
that observer enriched astronomy, that we cannot hesitate to bring them
forward at once.

I read the following passage in a Memoir by Lalande, printed in 1783,
and forming part of the preface to vol. viii. of the _Ephemerides of the
Celestial Motions_.

"Each time that Herschel undertakes to polish a mirror (of a telescope),
he condemns himself to ten, or twelve, or even fourteen hours' constant
work. He does not quit his workshop for a minute, not even to eat, but
receives from the hands of his sister that nourishment without which one
could not undergo suc