concerning Campanus' Euclid edition, it would be correct to
say that the enunciations (i.e. the propositions) which
Campanus gives are nearly identical with those of the
so-called "Adelard II" version. (The name "Adelard II" comes
from Clagett's article in 1953. I would prefer to call it
"Version II" because iwe now know that the text was not
written by Adelard of Bath.) The enunciations of "Version
II" are based to a great extent upon Arabic sources (the
translation by Adelard of Bath, i.e. Clagett's "Adelard I").
Therefore the enunciations of the Campanus text indirectly
go back to Arabic sources. But the proofs which Campanus
gives are totally different from the proofs in any Arabic
Euclid text. Many of Campanus' proofs are very long and
contain additional material from contemporary authors or by
Campanus himself.
As to your earlier e-mail: It is true that in many Campanus
manuscripts (e.g. in Paris, BN, lat. 7213, which you cite)
in the title it is said that the text was translated by
Adelard from the Arabic into Latin. But this ascription is
not correct, as recent authors (especially Dr. Busard; see
the references and reviews which Julio mentions) have shown.
I know about 130 manuscripts which transmit the Campanus
text of Euclid. They are listed (together with the
manuscripts of all other medieval Western Euclid versions)
in a booklet "Euclid in Medieval Europe" which was published
in Winnipeg in 1989. It is out of print, but I have many
copies in my office. If anyone is interested to get a free
copy, I would be pleased it to him or her.
Concerning the "oldest" Euclid manuscript: There are (at
least) three papyri from the 2nd to the 4th century AD which
contain small parts of the first and the second book of
Euclid's Elements. These papyri were edited in 1898, 1900,
and 1936, and their text was reprinted by E. S. Stamatis in
his Euclid edition (Euclidis Elementa. Vol. I. Libri I-IV
cum appendicibus. Post I. L. Heiberg edidit E. S. Stamatis.
Leipzig, 1969, pp.187-190).
Menso Folkerts