about

Historical, philological, and archival provenance for geometor.petersen.

Primary Textual Witnesses

  • 1866 Danish Editio Princeps (Karl Schønbergs Forlag, Kjøbenhavn): Methoder og Theorier til Løsning af geometriske Konstruktionsopgaver, anvendte paa ca. 400 Opgaver, written while Julius Petersen (1839–1910) taught in Copenhagen prior to his 1871 doctorate (Om Ligninger, der løses ved Kvadratrod) and appointment at the Polyteknisk Læreanstalt (1871) and University of Copenhagen (1887).

  • 1879 Authorized English Edition (Andr. Fred. Høst & Son, Copenhagen / Sampson Low, Marston, Searle & Rivington, London): Methods and Theories for the Solution of Problems of Geometrical Constructions, Applied to 410 Problems, translated from the expanded second Danish edition by Sophus Haagensen, Cand. Polyt. C. E. (8 + 102 pages, 100% Public Domain). Visually inspected page-by-page at high resolution from archival witnesses (HathiTrust uc1.31822009486531, UC San Diego digitization, and Bayerische Staatsbibliothek bsb11394923; documented in resources/methods_and_theories/sources_manifest.json).

  • 1879 Pre-Lindemann Historical Witness (p. 101): Appearing three years before Ferdinand von Lindemann’s June 1882 proof of the transcendence of \(\pi\), page 101 of Petersen’s Appendix preserves the striking contemporary testimony that while angle trisection (Problem 409) is demonstrably impossible via quadratic radicals, the impossibility of expressing \(\pi\) by square roots “as yet, nobody has been able to prove”.

Architecture & Content/Code Separation

In accordance with GEOMETOR Digital Scriptorium standards:

  • Historical Book Codex (docsrc/methods_and_theories/): Synchronized 3-track :layout: book edition (English 1879 · Summary · Notes) with calibrated standalone .euclid-graphic SVGs and interactive :g:, :person:, :cite:, and :term: apparatus—containing zero embedded py_file scripts.

  • Executable Constructive Library (src/geometor/petersen/, demos/, docsrc/demos/): Pure symbolic geometor.model constructors, CLI exporter, and standalone Rich-formatted Python demonstrations.