In 1874, Frege completed his Habilitationsschrift, entitled Rechnungsmethoden, die sich auf eine Erweiterung des Grössenbegriffes gründen (“Methods of Calculation Based on an Extension of the Concept of Quantity”). Immediately after submitting this thesis, the good offices of Abbe led Frege to become a Privatdozent (Lecturer) at the University of Jena.  Library records from the University of Jena establish that, over the next 5 years, Frege checked out texts in mechanics, analysis, geometry, Abelian functions, and elliptical functions (Kreiser 1984,   21).[1]   No doubt, many of these texts helped him to prepare the lectures he is listed as giving by the University of Jena course bulletin, for these lectures are on topics that often match the texts, i.e., analytic geometry, elliptical and Abelian functions, algebraic analysis, functions of complex variables, etc. (Kratzsch 1979).[2]