The edition of Iohannes de Sacro Bosco "Tractatus de Sphæra" published around 1478 has been made available by the Bibliothèque Nationale de Paris in facsimile PDF format. It can be consulted and downloaded at this address: http://gallica.bnf.fr/scripts/ConsultationTout.exe?O=N058736      This edition has been transcribed and is now available in text PDF format (see instructions below).      The page divisions were maintained but the line breaks were not kept in this edition. The punctuation follows the original but the original orthography was not maintained because it contained many abbreviations special symbols and spelling peculiarities. Hence, we hope that this edition will be easier to read than the facsimile version.        The text of this edition (and of all editions published in the 15th and 16th centuries) is quite different from Lynn Thorndike's edition, published in:

THORNDIKE, Lynn. The Sphere of Sacrobosco and its commentators. Chicago: University of Chicago Press, 1949.

     Thorndike's edition was based upon a number of manuscripts, and he did not intend to produce an edition that would represent the published editions. At several places, in his work, he points out that the text of published editions differ from the manuscripts (see, for instance: page 100, footnote 5; page 108, footnote 16; page 109, footnote 41). However, he did not stress those differences, and for that reason Thorndike's edition is usually regarded as the standard version of Sacrobosco's Tractatus.
     A comparison between several early published editions of Sacrobosco's book show a very strong similarity between them, and systematic differences between them and Thorndike's edition. Therefore, if one is interested in studying the version of Sacrobosco's book that was read from the late 15th century onwards, Thorndike's version may be misleading. Hence, the edition presented here may be useful, not as a replacement of Thorndike's, but as a complement to his work.

    This new edition of Sacrobosco's book can be downloaded in two printing formats (with identical content). In both cases, two pages of Sacrobosco's work are printed in a single page, to save paper, because this edition of Sacrobosco's book was printed in small pages.
     The first file is intended to produce a nice booklet. One should print the odd pages first, and then the even pages at the rear of the odd pages. By folding the printed set, one will have an adequately paginated booklet.

http://www.ghtc.usp.br/server/Download/Sacrobosco-1478.PDF (852 kb)

     The second one will print two pages of the Tractatus in each A4 paper page, in direct order, and will not produce a nice booklet, but it might be easier to print and the handle.

http://www.ghtc.usp.br/server/Download/Sacrobosco-1478-r.PDF (869 kb)

    It is also possible to consult this edition online, at this address:

http://www.ghtc.usp.br/server/Sacrobosco-1478.htm

    However, it is a very large file, and it may take a long time to display. It should be viewed using Internet Explorer, otherwise it will not be presented correctly. If you try to print this file, it will not have adequate page division. Therefore, we strongly suggest you to dowload and print one of the above PDF versions.