Part 37 (1/2)

[Footnote 918: _Astr. Nach._, No. 263 (1834); _Pop. Vorl._, pp. 615-620 (1838).]

[Footnote 919: _Outlines of Astr._, par. 431.]

[Footnote 920: _Month. Not._, vol. xxv., p. 61.]

[Footnote 921: _Month. Not._, vol. xxv., p. 264.]

[Footnote 922: _Astroph. Jour._, vol. vi., p. 422.]

[Footnote 923: _Harvard Annals_, vol. x.x.xii., p. 81.]

[Footnote 924: _Astr. and Astrophysics_, vol. xi., p. 778.]

[Footnote 925: Neison, _The Moon_, p. 25.]

[Footnote 926: _Knowledge_, vol. xvii., p. 85.]

[Footnote 927: Neison, _The Moon_, p. 104.]

[Footnote 928: The combination of a uniform rotational with an unequal orbital movement causes a slight swaying of the moon's globe, now east, now west, by which we are able to see round the edges of the averted hemisphere. There is also a ”parallactic” libration, depending on the earth's rotation; and a species of nodding movement--the ”libration in lat.i.tude”--is produced by the inclination of the moon's axis to her orbit, and by her changes of position with regard to the terrestrial equator. Altogether, about 2/11 of the _invisible_ side come into view.]

[Footnote 929: _Cel. Objects_, p. 58 (4th ed.).]

[Footnote 930: _Astr. Nach._, No. 1,631.]

[Footnote 931: Cf. Leo Brenner, _Naturwiss. Wochenschrift_, January 13, 1895; _Jour. Brit. Astr. a.s.s._, vol. v., pp. 29, 222.]

[Footnote 932: Respighi, _Les Mondes_, t. xiv., p. 294; Huggins, _Month.

Not._, vol. xxvii., p. 298.]

[Footnote 933: Birt, _Ibid._, p. 95.]

[Footnote 934: _Report Brit. a.s.s._, 1872, p. 245.]

[Footnote 935: _Observatory_, vol. xv., p. 250.]

[Footnote 936: _Astr. Reg._, vol. xvi., p. 265; _Astr. Nach._, No.

2,275.]

[Footnote 937: Lindsay and Copeland, _Month. Not._, vol. x.x.xix., p.

195.]

[Footnote 938: _Observatory_, vols. ii., p. 296; iv., p. 373. N. E.

Green (_Astr. Reg._, vol. xvii., p. 144) concluded the object a mere ”spot of colour,” dark under oblique light.]

[Footnote 939: Webb, _Cel. Objects_, p. 101.]

[Footnote 940: _Publ. Lick Observatory_, vol. iii., p. 7.]