[Footnote 556: _Comptes Rendus_, t. lxxiii., p. 434.] [Footnote 557: _Wash. Obs._, 1867, App. ii., p. 195.] [Footnote 558: Stokes, Anniversary Address, _Nature_, vol. xxxv., p. 114.] [Footnote 559: _Comptes Rendus_, t. ci., p. 50.] [Footnote 560: _Harvard Annals_, vol. xviii., p. 99.] [Footnote 561: Wesley, _Phil. Trans._, vol. clxxx., p. 350.] [Footnote 562: _Harvard Annals_, vol. xviii, p. 108.] [Footnote 563: _Lick Report_, p. 20.] [Footnote 564: _Ibid._, p. 14.] [Footnote 565: _Ibid._, p. 155.] [Footnote 566: _Pub. Astr. Soc. of the Pacific_, vol. iii., p. 158.] [Footnote 567: Professor Holden concluded, with less qualification, "that so-called 'polar' rays exist at all latitudes on the sun's surface." _Lick Report_, p. 19.] [Footnote 568: Holden, _Report on Eclipse of December, 1889_, p. 18; Charroppin, _Pub. Astr. Soc. of the Pacific_, vol. iii., p. 26.] [Footnote 569: Published as the Frontispiece to the _Observatory_, No. 160.] [Footnote 570: Wesley, _Ibid._, p. 107.] [Footnote 571: _Lick Observatory Contributions_, No. 4, p. 108.] [Footnote 572: _Astr. and Astrophysics_, vol. xiii. p. 307.] [Footnote 573: Lockyer, _Phil. Trans._, vol. clxxxvii., p. 592.] [Footnote 574: He died in London, November 20, 1898.] [Footnote 575: _Bull. Acad. St. Pétersbourg_, t. vi., p. 253.] [Footnote 576: W. H. Wesley, _Phil. Trans._, vol. cxc, p. 204.] [Footnote 577: _Lick Reports on Eclipse of January 1, 1889_, p. 204.] [Footnote 578: _Astroph. Jour._, vol. xi., p. 226.] [Footnote 579: _Observatory_, vol. xxi., p. 157.] [Footnote 580: _The Indian Eclipse_, 1898, p. 114.] [Footnote 581: _Science_, June 22, 1900; _Astroph. Jour._, vol. xii., p. 370.] [Footnote 582: _Ann. der Physik_, Bd. xlviii., p. 528. See also Wood, _Physical Review_, vol. iv., p. 191, 1896.] [Footnote 583: _Science_, August 3, 1900.] [Footnote 584: _Lick Observatory Bulletin_, No. 9.] [Footnote 585: _Observatory_, vol. xxiv., pp. 321, 375.] [Footnote 586: _Lick Report on Eclipse of December 22, 1889_, p. 47; _Month. Not._, vol. l., p. 372.] [Footnote 587: _Lick Obs. Bull._, No. 9.] [Footnote 588: _Bull. de l'Acad. St. Pétersbourg_, t. iv., p. 289.] [Footnote 589: _The Solar Corona discussed by Spherical Harmonics_, Smithsonian Institution, 1889.] [Footnote 590: Bakerian Lecture, _Proc. Roy. Soc._, vol. xxxix.] [Footnote 591: _Astr. and Astrophysics_, vol. xi., p. 483.] [Footnote 592: _Ibid._, vol. xii., p. 804.] [Footnote 593: _Am. Journ. of Science_, vol. xi., p. 253, 1901.] [Footnote 594: See Huggins, _Proc. Roy. Soc._, vol. xxxix., p. 108; Young, _North Am. Review_, February, 1885, p. 179.] [Footnote 595: Professor W. A. Norton, of Yale College, appears to have been the earliest formal advocate of the Expulsion Theory of the solar surroundings, in the second (1845) and later editions of his _Treatise on Astronomy_.] CHAPTER IV _SOLAR SPECTROSCOPY_