Based on manuscript evidence, the article presents a study of the historical and textual traditions of a fragment of Arabic mechanics which is also edited in Arabic and translated into English. This fragment, entitled Nutaf min al-hiyal, presents an Arabic translation of the theoretical part of the Probelama mechanica, a famous treatise of ancient mechanics attributed to Aristotle.
The article examines the Arabic tradition of the Problemata Mechanica, a Greek text of mechanical questions ascribed to Aristotle, which in some recent publications was claimed to have been unknown in the Arabic traditions. Against this claim, it will be shown that the Arab-Muslim scholars had access to the text at least in the form of an abridged version entitled Nutaf min al-hiyal included by Abd-ul-Rahmān al-Khāzinī (12th century) in the fifth part of his Kitāb mīzān al-hikma (Book of the balance of wisdom). Completed in 515 H (1121-22 CE), the Book of the balance of wisdom is the most important and comprehensive work on mechanics in the Middle Ages, from any cultural area and a real mine of information on mechanical knowledge up to the early 12th century.
In order to make it available to interested readers, the Arabic text of Nutaf min al-hiyal is edited hereinafter and translated into English. It is also accompanied with historical and textual commentaries.
Figure 1: Cover page of Kitāb mīzān al-hikma (Hyderabad edition, 1359 H /1940).
The Problemata Mechanica is a Greek treatise ascribed to Aristotle, but composed very probably by one of his later disciples. It deals with simple machines and many concrete phenomena on the basis of a constant procedure: the attempt to reduce them to the balance, and hence to the ‘marvellous properties' of the circle. Apparently completely unknown during the European Middle Ages, the text was printed in Venice in 1497 on the basis of a manuscript brought from Byzantium; it exerted then a considerable influence on the mechanical debates in the 16th century. It was long claimed that the Peripatetic Mechanica had not entered Arabic culture. It is possible now to affirm that this is not true, and that the scholars of the Islamic lands had access to it at least through a short text entitled Nutaf min al-hiyal (Elements/extracts of mechanics) edited in the 5th Book of Kitāb mīzān al-hikma. The Arabic text of Al-Khāzinī's encyclopaedia of ancient and medieval mechanics was published only once in 1359 H (1940 CE) in Hyderabad, India (under the auspices of the famous Uthmāniya -or Osmania- society). The text of the Nutaf occupies in this publication the pages 98 to 100. On the basis of several pieces of evidence, historical and conceptual, the summarizing of the introductory part of the Mechanical Problems and its structuring in the form of an epitome seems to be the work of al-Isfizārī (11th-12th centuries), al-Khāzinī's immediate predecessor and his master in mechanics.
Figure 2: Beginning of the Nutaf fragment in Kitāb mīzān al-hikma (Saint Petersburg, Russian National Library, Khanikoff collection, MS 117, folio 66b).
The text of the Nutaf min al hiyal represents indeed a significant partial Arabic version of the Mechanical Problems. Presented under a special title that indicates its character as an excerpt from a longer text, it is attributed directly to Aristotle. Beginning with the sentence: "Aristotle said", it consists in a reliable abridged version of the preliminary two sections of the pseudo-Aristotelian text where the theoretical foundation of the treatise is disclosed. Thus, it includes a methodically arranged compendium of the introduction giving a definition of mechanics and of Problem 1 on the reason of the accurateness in the larger balances to the detriment of smaller ones.
As edited in Kitāb mīzān al-hikma, the Nutaf is preceded by a relatively long technical discussion on the balance equilibrium dealing with the different cases of incidence of the axis on the balance beam. In his analysis of this question, al-Khāzinī probably had in mind the Peripatetic Problem 2 which investigates the accidents that arise from the suspension of the balance beam from above or from below. Without our assuming the analysis of the balance equilibrium in Kitāb mīzān al-hikma to be closely connected to Pseudo-Aristotle's second mechanical question, it is hardly possible to understand why the Nutaf fragment was inserted precisely at the place it occupies in the middle of the first chapter of the fifth part of al-Khāzinī's large book. Logically, it this was done in order to provide a theoretical foundation for the discussion of the balance equilibrium problem.
Book Five of Kitāb mīzān al-hikma is dedicated to the description and the trial of the balance of wisdom, a huge lever balance with equal arms having five scale-pans and a running counterweight. Its first chapter – entitled "on the construction of the limbs of the balance of wisdom according to the figure indicated by the eminent master… al-Isfizārī" – consists of a very minute description of this complex instrument, probably according to written specifications by al-Isfizārī, whose name is mentioned three times in the chapter. The Nutaf fragment extracted from the Aristotelian Mechanica is introduced at the end of Section 4, following what might be considered the most important part of al-Isfizārī's description. This suggests that the paternity of the latter is valid for all the material enclosed in the limits of the chapter, including the fragment derived from the Peripatetic treatise. On this basis, he might be considered logically as responsible for the adaptation of this partial Arabic digest and also for its insertion as a digression appended to the description of the parts of the balance. We owe to al-Khāzinī's predecessor indeed a whole body of recensions, reworkings, and commentaries that comprise virtually the whole corpus of theoretical mechanics to which he could have access, including Greek and Arabic works.
Indeed, the archives in different libraries preserve a collection of summaries extracted from the mechanical works of Greek and Arabic authors and related to the name of al-Isfizārī. This collection, which has never been studied before, exists in two manuscript copies: MS 351 in the John Ryland Library in Manchester and MS QO 620 H-G in the ‘Uthmāniyya University Library in Hyderabad. Up till now, it has been mentioned only in the catalogues of Arabic manuscripts. It includes, in this order: a long reworked version of BanūMusā's Kitāb al-hiyal (Book of mechanics), a commentary on selected parts of the first two books of Heron's Mechanics, and a short text entitled Kitāb fī al-bakara (Book of the wheel) ascribed to Apollonius, probably an extract from the text on the screw ascribed to Apollonius of Perga by Proclus and Pappus.
Therefore, in the light of this information, it would be quite natural that he would produce a compendium of the Mechanical Problems, one of the major texts of ancient mechanics.
Figure 3: Andhra Pradesh Government Oriental Manuscripts Library and Research Institute in Hayderabad, Codex Riyādhī 125, p. 82. Note the title of the text Nutaf min al-hiyal (indicated by the red arrow) written in the manuscript in a colourful ink.
The existence of an Arabic version of the Mechanical Problems has been left unconsidered in recent historiographical debates. Surprisingly, however, the German scholar Thomas Ibel had identified the passage in Kitāb mīzān al-hikma as a partial Arabic version of the Peripatetic text, which he also translated into German (Thomas Ibel, Die Wage im Altertum und Mittelalter, Erlangen, 1908, pp. 123-125). Nonetheless, this brilliant achievement remained unnoticed, and none of the scholars who investigated the field of Arabic mechanics since then referred to it nor happened to identify the corresponding passage in al-Khāzinī's book when the latter was published in 1940. Rather, recent works relied heavily on the claimed non-transmission of the Peripatetic treatise to Arabic culture, and drew from this ‘fact' general conclusions relevant to the reconstruction of its textual history and to the determination of its place in the history of mechanics. In this regard, the passage preserved by al-Khāzinī provides a decisive proof confirming the Graeco-Arabic transmission of the text and stands as an argument in favor of the possible existence of a complete Arabic version, longer than the short summary provided in the Nutaf.