[Footnote 20: _Phil. Trans._, vol. xcv., p. 233.]
[Footnote 21: _Ibid._, vol. xcvi., p. 205.]
[Footnote 22: "Ingens bolus devorandus est," Kepler admitted to Herwart in May, 1603.]
[Footnote 23: Described in "Præfatio Editoris" to _De Revolutionibus_, p. xix. (ed. 1854).]
[Footnote 25: _Phil. Trans._, vol. xvii., p. 848.]
[Footnote 26: _Ibid._, vol. lxxii., p. 97.]
[Footnote 27: Doberck, _Observatory_, vol. ii., p. 110.]
[Footnote 28: _Phil. Trans._, vol. lvii., p. 249.]
[Footnote 29: _Ibid._, vol. lxxiv., p. 56.]
[Footnote 30: _Beobachtungen von Fixsterntrabanten_, 1778; and _De Novis in Coelo Sidereo Phænomenis_, 1779.]
[Footnote 32: _Phil. Trans._, vol. lxxii., p. 162.]
[Footnote 33: _Ibid._, vol. lxxiii., p. 272.]
[Footnote 34: _Ibid._, vol. xciii., p. 340.]
[Footnote 35: _Phil. Trans._, vol. lxxv., p. 255.]
[Footnote 36: _Ibid._, vol. lxxix., pp. 214, 222.]
[Footnote 37: _Ibid._, vol. xcii., pp. 479, 495.]
[Footnote 38: _Phil. Trans._, vol. ci., p. 269.]
[Footnote 39: _Ibid._, vol. cvii., p. 311.]
[Footnote 40: Bullialdus, _De Nebulosâ Stellâ in Cingulo Andromedæ_ (1667); see also G. P. Bond, _Mém. Am. Ac._, vol. iii., p. 75, Holden's Monograph on the Orion Nebula, _Washington Observations_, vol. xxv., 1878 (pub. 1882), and Lady Huggins's drawing, _Atlas of Spectra_, p. 119.]
[Footnote 41: _Mathemata Astronomica_, p. 75.]
[Footnote 42: _Systema Saturnium_, p. 9.]
[Footnote 43: _Phil. Trans._, vol. xxix., p. 390.]
[Footnote 44: _Mém. Ac. des Sciences_, 1755.]
[Footnote 45: _Conn. des Temps_, 1784 (pub. 1781), p. 227. A previous list of forty-five had appeared in _Mém. Ac. des Sciences_, 1771.]
[Footnote 46: _Phil. Trans._, vol. lxxiv., p. 442.]
[Footnote 47: _Ibid._, vol. lxxix., p. 213.]
[Footnote 48: _Ibid._, vol. lxxv., p. 254.]
[Footnote 49: _Ibid._, vol. lxxix., p. 225.]
[Footnote 50: _Phil. Trans._, vol. lxxix., p. 226.]
[Footnote 51: _Ibid._, vol. lxxxi., p. 72.]
[Footnote 53: _Phil. Trans._, vol. ci., p. 271.]
[Footnote 55: J. Herschel, _Phil. Trans._, vol. cxvi., part iii., p. 1.]
[Footnote 56: His own words to the poet Campbell cited by Holden, _Life and Works_, p. 109.]
[Footnote 57: _Phil. Trans._, vol. civ., p. 283.]
We have now to consider labours of a totally different character from those of Sir William Herschel. Exploration and discovery do not constitute the whole business of astronomy; the less adventurous, though not less arduous, task of gaining a more and more complete mastery over the problems immemorially presented to her, may, on the contrary, be said to form her primary duty. A knowledge of the movements of the heavenly bodies has, from the earliest times, been demanded by the urgent needs of mankind; and science finds its advantage, as in many cases it has taken its origin, in condescension to practical claims. Indeed, to bring such knowledge as near as possible to absolute precision has been defined by no mean authority[58] as the true end of astronomy.