ii.--A Third Catalogue of the
comparative Brightness of the Stars; with an Introductory Account
of an Index to Mr. Flamsteed's Observations of the Fixed Stars,
contained in the Second Volume of the Historia Coelestis to which
are added several useful Results derived from that
Index.--Observations of the changeable Brightness of the Satellites
of Jupiter, and of the Variation in their apparent Magnitudes; with
a Determination of the Time of their rotary Motions on their Axes,
to which is added a Measure of the Diameter of the Second
Satellite, and an Estimate of the comparative Size of the Fourth.

1798. _Phil. Trans._, vol. lxxxviii.--On the Discovery of Four
additional Satellites of the Georgium Sidus. The retrograde Motion
of its old Satellites announced; and the Cause of their
Disappearance at certain Distances from the Planet explained.

1799. _Phil. Trans._, vol. lxxxix.--A Fourth Catalogue of the
comparative Brightness of the Stars.

1800. _Phil. Trans._, vol. xc.--On the Power of penetrating into
Space by Telescopes, with a comparative Determination of the Extent
of that Power in Natural Vision, and in Telescopes of various Sizes
and Constructions; illustrated by select
Observations.--Investigation of the Powers of the Prismatic Colours
to heat and illuminate Objects; with Remarks that prove the
different Refrangibility of radiant Heat; to which is added an
Inquiry into the Method of viewing the Sun advantageously with
Telescopes of large Apertures and high magnifying
Powers.--Experiments on the Refrangibility of the Invisible Rays of
the Sun.--Experiments on the Solar and on the Terrestrial Rays that
occasion Heat; with a comparative View of the Laws to which Light
and Heat, or rather the Rays which occasion them, are subject, in
order to determine whether they are the same or different.

1801. _Phil. Trans._, vol. xci.--Observations tending to
investigate the Nature of the Sun, in order to find the Causes or
Symptoms of its variable Emission of Light and Heat; with Remarks
on the Use that may possibly be drawn from Solar
Observations.--Additional Observations tending to investigate the
Symptoms of the variable Emission of the Light and Heat of the Sun;
with Trials to set aside darkening Glasses, by transmitting the
Solar Rays