Complete Works of Euclid, Vol. 7 (Optics and Catoptrics)

p. 170, 12 τοὔμπροσθεν] τοὔμπροσθε
p. 172, 3 B] to be omitted
p. 180, 22 BK, ΓKΔ] BKΔ; see Optica genuina p. 36, 23
p. 188, 28 ἡμικυκλίου] ἡμικυλίνδρου
p. 196, 25 ὁ BΓ] ὁ περὶ τὴν BΓ. In the figure, Γ should be placed where BΔ appears to cut the circle, although it is obscured in this way, that it is perpendicular to the plane of the circle.
p. 226, 9 ΔEZ] ὑπὸ ΔEZ (for AEB write ὑπὸ AEB)
p. 238, 24 ἀποχωροῦν] ἀποχωρείτω; one should write ἀποχωρεῖ or perhaps ἀποχωρεῖται (see p. 110, 26)
p. 240, 21 καί — 22 φέρεσθαι] to be omitted
p. 166, 7; 180, 23 to be omitted, which I have enclosed in brackets.

Perhaps also p. 224, 3, 4, 5, 7, 10 should be replaced with A instead of Δ along with V, lest Δ be used twice; then A should be deleted in the first figure on p. 223 and on p. 224, 3 one should write ΘNA with V m. rec. More doubtful are the passages p. 190, 12—14; 196, 3, because there the correction was not made by a recent hand; but I would believe that here, too, the first hand should be followed.

Cod. 6 is closest to V and without doubt, as in Eutocius (see Apollon. II p. VI), it was copied from V itself. For not only does it agree with V almost alone at p. 146, 16; 148, 9; 160, 11; 166, 20; 168, 14; 188, 28; 196, 25; 238, 24; 240, 21, but it also often has the same errors, such as at p. 148, 15; 152, 1; 170, 8, 9; 182, 13; 192, 24; 202, 15; 212, 4 (see p. 208, 11), and the better readings it possesses (p. 148, 21; 150, 9, 10, 14, 19; 152, 8; 170, 12; 172, 3) were readily available to that skilled and bold scribe (see Apollon. II p. VII); at p. 148, 17 he added ἅμα without necessity, at p. 208, 11 he falsely wrote ABΓΔ. It must also be mentioned that cod. 6 alone has the scholia of codex V, nos. 82, 84, 85, and the reasoning of the numbers in 82, concerning which see p. 278, is best explained from V. But we have already seen above, p. XIX, that the scribe of codex 6 also had another codex; see what at p. 182, 13—15 it has the reading of the recent hand of codex V in the margin with the addition of ἐν ἄλλῳ. That copies of the genuine recension were also available to him is apparent from scholium 21 p. 259, 8. Cod. 6 was corrected by a more recent hand to the likeness of the corrected codex V (p. 144, 1 ὁ Εὐκλείδης, 4 γινομένας, p. 146, 12 πυκτίον, 20 ἀξιοῖ, p. 148, 3 οὖν ὡς, p. 150, 23 πρὸς ἀντίληψιν τῶν ὁρατῶν, p. 162, 3 ἡ KM, p. 172, 9 τῶν ἄρα ἴσων μεγεθῶν, all m. 2; p. 190, 12 διά — 14 ὁραθήσεται mg. m. 2).

From V were also copied codices 5 and 10; for they have in the text the interpolations added in it by a recent hand (even those which do not exist in cod. 6)