In 1825 he commenced a careful re-examination of the numerous
nebulae and starry clusters which had been discovered by his father, and
described in the "Philosophical Transactions," fixing their positions
and investigating their aspects. He devoted eight years to this _magnum
opus_, completing it in 1832. The catalogue which he then contributed to
the "Philosophical Transactions" includes 2306 nebulae and
star-clusters, of which 525 were discovered by himself. While engaged in
this difficult task, Herschel discovered between three and four thousand
double stars, which he described in the Memoirs of the Astronomical
Society. His observations were made with an excellent Newtonian
telescope, twenty feet in focal length, and eighteen and a half inches
in aperture; and having obtained, to use his own expression, "a
sufficient mastery over the instrument," the idea occurred to him of
making it available for a survey of the southern heavens. Accordingly,
he left England on the 13th of November 1833, and arrived at Cape Town
on the 16th of January 1834.
Pages:
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82