ed by Herschel at 10h. 16m.
1795 Herschel's theory of the solar constitution.
1796 Herschel's first measures of comparative stellar
brightness.
1796 Laplace's Nebular Hypothesis published in _Exposition
du Systeme du Monde_.
1797 Publication of Olbers's method of computing
cometary orbits.
1798 Retrograde motions of Uranian satellites detected
by Herschel.
1799 Publication of first two volumes of _Mecanique Celeste_.
1799, May 7 Transit of Mercury observed by Schroeter.
1799, Nov. 12 Star-shower observed by Humboldt at Cumana.
1800 _Monatliche Correspondenz_ started by Von Zach.
1800 Invisible heat-rays detected in the solar spectrum
by Herschel.
1801, Jan. 1 Discovery of Ceres by Piazzi.
1801 Publication of Lalande's _Histoire Celeste_.
1801 Investigation by Herschel of solar emissive variability
in connection with spot-development.
1802, March 28 Discovery of Pallas by Olbers.
1802 Herschel's third Catalogue of Nebulae.
1802 Herschel's discovery of binary stars.
1802 Marks of clustering in the Milky Way noted by Herschel.
1802 Wollaston records seven dark lines in the solar
spectrum.
1802, Nov. 9 Transit of Mercury observed by Herschel.
1804, Sept. 2 Discovery of Juno by Harding.
1804 Foundation of Optical Institute at Munich.
1805 Herschel's second determination of the solar apex.
1807, March 29 Discovery of Vesta by Olbers.
1811 Herschel's theory of the development of stars from
nebulae.
1811, Feb. 9 Death of Maskelyne. Pond appointed to succeed him
as Astronomer-Royal.
1811, Sept. 12 Perihelion passage of great comet.
1812 Theory of electrical repulsion in comets originated
by Olbers.
1812, Sept. 15 Perihelion passage of Pons's comet.
1814 Herschel demonstrates the irregular distribution of
stars in space.
1815 Fraunhofer maps 324 dark lines in the solar spectrum.
1818 Publication of Bessel's _Fundamenta Astronomiae_.
1819 Recogni