130 
HISTORY OF THE 
[1860-70 
We see greatly increased activity in the observation of 
meteors and meteor radiants, and also the establishment of the 
identity of orbits of certain comets and meteors. 
We see great advances in the determination of the solar parallax, 
great advances in planetary theory, and great advances in lunar 
theory. 
We see the development of the idea that the lunar acceleration 
must be connected with tidal friction and the consequent lengthen 
ing of the day. 
We see the figure of the earth defined in terms of a possible 
ellipsoid. 
We see the number of minor planets carried well beyond the 
first century, the hundredth being named after that goddess of 
mischief, Hecate. 
We see the completion of Argelander’s Bonn Durchmusterung , 
and the publication of the following notable contributions :— 
Sir John Herschel’s General Catalogue of 5079 Nebulae (1864). 
Lassell’s (Marth’s) Catalogue of 600 Neiv Nebulae (1867). 
Rosse’s Observations of Nebulae with his 6-foot Speculum (1861). 
Carrington’s Memoir on Sun Spots (1863). 
De la Rue’s Memoir on the Solar Eclipse, i860 July 18 (1862). 
Tennant’s Memoir on the Solar Eclipse, 1868 August 17-18 
(1869). 
De la Rue and Balfour Stewart’s Heliographic Positions and 
Areas of Sun Spots (1862). 
Huggins and Miller’s work on The Spectra of the Stars and 
Nebulae (1864). 
Dunkin’s Memoir on the Motion of the Sun in Space (1864). 
Lockyer’s early work in Solar Physics (1868). 
Huggins’s Memoir on his Attempt to determine whether Stars 
are moving towards or from the Earth (1868). 
Bond’s monograph on Donati’s Comet (1862). 
Thomson’s paper on The Rigidity of the Earth (1863). 
Airy’s work on The Diurnal Variation of Magnetic Elements. 
Chauvenet’s Spherical and Practical Astronomy (1863). 
Watson’s Theoretical Astronomy (1868). 
The decade was notable, too, for several remarkable astronomical 
events. 
The earth passed through the tail of a comet (1861). 
The star T Coronae blazed out with great brilliance (1866 
May). 
The long-expected November meteors made their memorable 
display (1866). 
There were tw r o solar eclipses which have become historically 
notable : i860 July 18, and 1868 August 17-18.