The item comprises observations made as Madras Equatorial Observations of Comet II; its observations were taken in July 1861 by N.R. Pogson.

The item comprises observations made as Madras Equatorial Observations of Comet Biela; its observations were taken in December 1872 by N.R. Pogson. Comet Biela (official designation: 3D/Biela) was a periodic Jupiter-family comet first recorded in 1772 by Montaigne and Messier and finally identified as periodic in 1826 by Wilhelm von Biela.

The item comprises observations made as Madras Equatorial Observations of Comet Encke; its observations were taken in August 1878 by N.R. Pogson. Encke's Comet (official designation: 2P/Encke) is a periodic comet that completes an orbit of the Sun once every 3.3 years.

The item comprises observations made as Madras Equatorial Observations of the 1882 comet; its observations were taken from September to November 1882 by N.R. Pogson. The Great Comet of 1882, formally designated C/1882 R1, 1882 II, and 1882b, was a comet that became very bright in September 1882.

The item comprises observations made as Madras Equatorial Observations of an unknown Comet; its observations were taken on 22 January 1884 by N.R. Pogson.

The item contains observation notes of the comet Tempel on 21 and 22 August 1862. Tempel 1 is a Jupiter-family comet.