Contents: Forerunner of Modern Science; Voynich Cipher Manuscript of Roger Bacon, a sketch of its history; Voynich Cipher Manuscript of Roger Bacon, sketch of its contents; Principles of Roger Bacon's Cipher; Following the Clues; Derivation of the Biliteral Alphabets; Script of the Shorthand Cipher; Rules for Deciphering the Texts; Interpretation of the Key; Annular Eclipse of 1290; Great Nebula of Andromeda; Comet of 1723; Cato and Fulvius; Oxford Story; Gunpowder Formula; Vatican Document; Paris Medical Text; Formula for Producing Metallic Copper; Abbreviated Word about the Green Lion; Tables of Values.