In the dedication of the work to the Pope it is stated that this edition was prepared by Domitius Calderinus of Verona, who promised to collate the Latin version with an ancient Greek manuscript; and that Conrad Sweinheim, who was one of the first who introduced the art of printing at Rome, undertook, with the assistance of “certain mathematical men,” whom he taught, to “impress” the maps upon plates of copper. Sweinheim, after having spent three years in preparing these plates, died before they were finished; and Arnold Bukinck, a learned German printer, completed the work, “that the emendations of Calderinus,--who also died before the book was printed,--and the results of Sweinheim’s most ingenious mechanical contrivances might not be lost to the learned world.”[IV-44] [Footnote IV-44: “Magister vero Conradus Suueynheyn, Germanus, a quo formandorum Romæ librorum ars primum profecta est, occasione hinc sumpta posteritati consulens animum ad hanc doctrinam capessendam applicuit. Subinde mathematicis adhibitis viris quemadmodum tabulis eneis imprimerentur edocuit, triennioque in hac cura consumpto diem obiit. In cujus vigilarum laborumque partem non inferiori ingenio ac studio Arnoldus Buckinck e Germania vir apprime eruditus ad imperfectum opus succedens, ne Domitii Conradique obitu eorum vigiliæ emendationesque sine testimonio perirent neve virorum eruditorum censuram fugerent immensæ subtilitatis machinimenta, examussim ad unum perfecit.”--Dedication to the Pope, of Ptolemy’s Cosmography, Rome, 1478.]