[490] _Nature_, June 25, 1874. [491] _Popular Astronomy_, May, 1895, "Reflectors or Refractors." [492] Denning, _Telescopic Work for Starlight Evenings_, p. 225. [493] _Nature_, November 2, 1893. [494] _Telescopic Work_, p. 226. [495] _Copernicus_, vol. i. p. 229. [496] Grant, _History of Physical Astronomy_, p. 433. [497] _Cosmos_, vol. ii. p. 699. [498] Grant, _History of Physical Astronomy_, p. 536, footnote. [499] _Bedford Catalogue_, p. 179. [500] _The Observatory_, July, 1891. [501] _Nature_, September 3, 1903. [502] _Cosmos_, vol. ii. p. 669. [503] _The World Machine_, p. 80. [504] _Ibid._, p. 89. [505] Grant, _History of Physical Astronomy_, p. 107. [506] Grant, _History of Physical Astronomy_, p. 113. [507] _Nature_, August 11, 1898. [508] _Ibid._, August 18, 1898. [509] _Ibid._, October 20, 1898. [510] _The Observatory_, vol. iv. (1881), p. 234. [511] W. T. Lynn, _The Observatory_, July, 1909, p. 291. [512] Quoted in _The Observatory_, July, 1902, p. 281. [513] _Astrophysical Journal_, vol. 6, 1897, p. 304. [514] _Celestial Cycle_, p. 367. [515] _The Observatory_, vol. 5 (1882), p. 251. [516] Quoted by Humboldt in _Cosmos_, vol. ii. p. 696, footnote. [517] Quoted by Denning in _Telescopic Work_, p. 347. [518] _Knowledge_, February 20, 1885, p. 149. [519] Humboldt's _Cosmos_, vol. i. p. 123. [520] _Outlines of Astronomy_, par. 319; edition of 1875. [521] _Bulletin de la Soc. Ast. de France_, March, 1908, p. 146. [522] An "astronomical unit" is the sun's mean distance from the earth. [523] This is on the American and French system of notation, but on the English system, 10{66} = 10{60} × 10{6} would be a million decillion. [524] _Astronomical Society of the Pacific_, April, 1909 (No. 125), and _Popular Astronomy_, May, 1909. [525] _Nature_, July 22, 1909. [526] _Ibid._ [527] _The Observatory_, vol. 9 (December, 1886), p. 389. [528] _De Nat. Deorum_, quoted in Smyth's _Cycle_, p. 19. [529] _The Observatory_, May, 1907. [530] _More Worlds than Ours_, p. 17. [531] _Man's Place in Nature._ Transcriber's Notes: Passages in italics are indicated by _italics_. Superscripted characters are indicated by {superscript}. Subscripted characters are indicated by _{subscript}. Foonote 48 appears on page 28 of the text, but there is no corresponding marker on the page. Foonote 448 appears on page 295 of the text, but there is no corresponding marker on the page. End of Project Gutenberg's Astronomical Curiosities, by J. Ellard Gore