[6] The distances do not represent the _total_ displacement, but only the displacement towards Washington in one case and towards Pulkowa in the other. Transcriber's Notes: Passages in italics are indicated by _italics_. Passages in bold are indicated by =bold=. Subscripted letters are indicated by {subscript}. The original text includes the Greek a, b, and g. For this text version these letters are presented as [alpha], [beta], and [gamma]. All side notes belonging to a single paragraph have been moved to the beginning of the paragraph. Sidenotes split across pages have been joined together. Punctuation has been corrected without note. Corrections in the "Errata" have been made in this text version. The following misprints have been corrected: "Hencke'" corrected to "Hencke's" (page 23 sidenote) "annouced" corrected to "announced" (page 45 sidenote) "are are" corrected to "are" (page 119) "Konigsberg" corrected to "Königsberg" (Index) Other than the corrections listed above, inconsistencies in spelling and hyphenation have been retained from the original. End of Project Gutenberg's Astronomical Discovery, by Herbert Hall Turner