Euclid, Elements
Thomas L. Heath, Sir Thomas Little Heath, Ed.

phrases are stereotyped and few in number, the technical terms are simply and consistently rendered, and the less formal expressions connect themselves as closely with the Greek as is consistent with intelligibility and the character of the Arabic language. Only in isolated cases does the formulation of definitions and enunciations differ to any considerable extent from the original. In general, his object seems to have been to get rid of difficulties and unevennesses in the Greek text by next devices, while at the same time giving a faithful reproduction of it.¹.

There are curious points of contact between the versions of al-[Hnull ]ajjāj and T[hnull ]amacr;bit-Is[hnull ]āq. For example, the definitions and enunciations of propositions are often word for word the same. Presumably this is owing to the fact that Is[hnull ]āq found these definitions and enunciations already established in the schools in his time, where they would no doubt be learnt by heart, and refrained from translating them afresh, merely adopting the older version with some changes². Secondly, there is remarkable agreement between the Arabic versions as regards the figures, which show considerable variations from the figures of the Greek text, especially as regards the letters; this is also probably to be explained in the same way, all the later translators having most likely borrowed al-[hnull ]ajjāj's adaptation of the Greek figures³. Lastly, it is remarkable that the version of Books XI.—XIII. in the Kjφbenhavn MS. (K), purporting to be by al-[Hnull ]ajjāj, is almost exactly the same as the Thābit-Is[hnull ]āq version of the same Books in O. Klamroth conjectures that Is[hnull ]āq may not have translated the Books on solid geometry at all, and that Thābit took them from al-[Hnull ]ajjāj, only making some changes in order to fit them to the translation of Is[hnull ]āq⁴.

From the facts (1) that a[tnull ]-[Tnull ]ĩsī's edition had the same number of propositions (468) as al-[hnull ]ajjāj's version, while Thābit-Is[hnull ]āq's had 478, and (2) that a[tnull ]-[Tnull ]ĩsī has the same careful references to earlier propositions, Klamroth concludes that a[tnull ]-[Tnull ]ĩsī deliberately preferred al-[hnull ]ajjāj's version to that of Is[hnull ]āq⁵. Heiberg, however, points out (1) that a[tnull ]-[Tnull ]ĩsī left out VI. 12 which, if we may judge by Klamroth's silence, al-[hnull ]ajjāj had, and (2) al-[hnull ]ajjāj's version had one proposition less in Books I. and III. than a[tnull ]-[Tnull ]ĩsī has. Besides, in a passage quoted by [hnull ]ājī Khalfa⁶ from a[tnull ]-[Tnull ]ĩsī, the latter says that “he separated the things which, in the approved editions, were taken from the archetype from the things which had been added thereto,” indicating that he had compiled his edition from both the earlier translations⁷.

There were a large number of Arabian commentaries on, or reproductions of, the Elements or portions thereof, which will be