Contents: Introduction, (1) The Libraries of Tycho Brahe & of Paul Wittich: The Misleading Attribution of the Copernican Annotations, Master Paul Wittich, Tycho's Attempts to Acquire Wittich's Library, & The Prague Tychoniana, (2) Wittich's Copernican Annotations: Reinhold's Annotations & the Liege "De revolutionibus", The Vatican Wittich Copy, The Prague & Wroclaw Wittich Copies, & Why Annotate Four Copes of "De revolutionibus"?, (3) Reconstructing the Universe: Tycho's Early Transformations & Wittich's Visit, A Theft in the Castle?: Thycho's "Legal Brief" on the Ursus Affair, & Ursus' Account & Kepler's Interpretation, & Constructing Tycho's Cosmology. Appendix: The Vatican Annotations, & Wittich's Obituary in "Silesia Togata." Illus.