tion by Encke of the first short-period comet.
1819, June 26 Passage of the earth through the tail of a comet.
1820 Foundation of the Royal Astronomical Society.
1821 Foundation of Paramatta Observatory.
1821, September First number of _Astronomische Nachrichten_.
1822, May 24 First calculated return of Encke's comet.
1822, August 25 Death of Herschel.
1823 Bessel introduces the correction of observations for
personal equation.
1823 Fraunhofer examines the spectra of fixed stars.
1824 Distance of the sun concluded by Encke to be
95-1/4 million miles.
1824 Publication of Lohrmann's Lunar Chart.
1824 Dorpat refractor mounted equatoreally.
1826 Commencement of Schwabe's observations of sun-spots.
1826, Feb. 27 Biela's discovery of a comet.
1827 Orbit of a binary star calculated by Savary.
1829 Completion of the Royal Observatory at the Cape of
Good Hope.
1829 The Koenigsberg heliometer mounted.
1830 Publication of Bessel's _Tabulae Regiomontanae_.
1832 Discovery by Brewster of "atmospheric lines" in the
solar spectrum.
1833 Magnetic observatory established at Gottingen.
1833, Nov. 12,13 Star-shower visible in North America.
1833 Completion of Sir J. Herschel's survey of the northern
heavens.
1834, Jan. 16 Sir J. Herschel's landing at the Cape.
1835, September Airy appointed Astronomer-Royal in succession to Pond.
1835, Nov. 16 Perihelion passage of Halley's comet.
1837 Solar movement determined by Argelander.
1837 Bessel's application of the heliometer to measurements
of stellar parallax.
1837 Publication of Beer and Maedler's _Der Mond_.
1837 Publication of Struve's _Mensurae Micrometricae_.
1837, Dec. 16 Outburst of Eta Carinae observed by Sir J. Herschel.
1837 Thermal power of the sun measured by Herschel and
Pouillet.
1838 Parallax of 61 Cygni determined by Bessel.
1839, Jan. 9 Parallax of Alpha Centauri announced by Henderson.
1839 Completion of Pulkowa Observatory.
1839 Solidity of the earth concluded by Ho