Samsó, Julio

Suhayl International Journal for the History of the Exact and Natural Sciences in Islamic Civilisation

Revistes Catalanes amb Accés Obert

367
Mohammed Abattouy and Salim al-Hassani, The corpus of al-Isfizārī in the sciences 
of weights and mechanical devices. New Arabic texts in theoretical and practical me-
chanics from the early XIIth century. English translation, partial analysis and historical 
context. Al-Furqān Islamic Heritage Foundation. Centre for the Study of Islamic Manu-
scripts. London, 2015. xvi + 403 pp.
In 2013, the Furqān Foundation published the critical edition of al-Isfizārī’s me-
chanical corpus prepared by Abattouy and Hassani (Matn al-Muẓaffar al-Isfizārī 
fī ‘ilmay al-athqāl wa l-ḥiyal. Taḥqīq naqdī wa-dirāsa tārīkhiyya li-nuṣūṣ jadīda 
fī taqlīd al-mīkānīkā al-‘arabiyya). Now, this edition is complemented by an 
English translation and commentary of the texts related to the science of weights.
Something should be said, first of all, about the author (see pp. 31-49): Abū 
Ḥātim al-Muẓaffar b. Ismā‘īl al-Isfizārī (ca. 1048- ca. 1116) is a relatively un-
known Iranian scientist who lived in the second half of the 11th and the beginning 
of the 12th century and was active in Isfahan and the area of Khurasan. Abattouy 
and Hassani have gathered some information about his life from the sources, 
two of which were written by authors who lived near al-Isfizārī’s own time: al-
Bayhaqī’s (d. 1169-70) Tatimmat ṣiwān al-ḥikma, and Niẓāmī ‘Arūḍī 
Samarqandī’s (d. 1161) Chahār maqāla, as well as Ibn al-Athīr’s (d. 1233) al-
Kāmil fī l-tārīkh. Al-Isfizārī was a contemporary of ‘Umar al-Khayyām (1048-
ca. 1123) with whom he worked at the Isfahan observatory founded by Malikshāh, 
which remained active between 1074 and 1092. In spite of this, and in spite of his 
interest in hay’a (astronomy or cosmology?), al-Isfizārī does not seem to have 
written any astronomical works, although he wrote books on theoretical and prac-
tical (misāḥa) geometry, meteorology, botany, natural science and mechanics, the 
last of which is the main focus of interest of this book.
Al-Isfizārī developed the two main branches of mechanics cultivated by Is-
lamic scientists in the Middle Ages (pp. 13-29): ‘Ilm al-athqāl (the science of 
weights) and ‘Ilm al-ḥiyal (the mechanics of machines). The former, which stud-
ies weights and their behaviour in balances, attracted the attention of Mohammed 
Abattouy some twenty years ago. Abattouy has focused on its development in 
Islamic lands, in which it was considered an independent discipline, between the 
9th and the 19th centuries and has discovered fifty-eight treatises on the topic; he 
compiled a useful list of thirty-two of these treatises for the proceedings of the 
16486_Suhayl.indd   367 20/11/17   11:42
368
Julio Samsó
symposium A shared legacy. Islamic science East and West held in Barcelona in 
2007 (published Barcelona, 2008, see pp. 92-99). The whole corpus contains 
translations from Greek sources (writings ascribed to Aristotle, Euclid, as well as 
authentic works by Archimedes, Heron and Pappus), original Arabic works writ-
ten between the 9th and the 12th centuries beginning with Thābit ibn Qurra’s (d. 
901) Kitāb fī l-qarasṭūn, and followed by practical texts dated between the 14th 
and the 19th centuries. The culminating point of this tradition is the Mīzān al-ḥikma 
of al-Khāzinī, probably a disciple of al-Isfizārī, which contained the description of 
an ideal balance able to measure absolute and specific weights, calculate exchange 
rates of currencies, and determine time. On the whole, as established by the authors 
of this volume, “the new Arabic science of weights was marked by a close combi-
nation of experimentation and mathematisation” (p. 26). Some of these works were 
translated into Latin – Gerard of Cremona, for example, translated Thābit’s 
qarasṭūn – and, thus, exerted an influence in the European science of weights 
which was born with Jordanus Nemorarius, in the 13th century.
Al-Isfizārī’s main contribution to the science of weights is to be found in the 
Irshād dhawī l-‘irfān ilā ṣinā‘at al-qaffān (“Guiding people of knowledge in 
the art of the steelyard”). This book is dedicated to Abū Sa‘īd Muḥammad b. 
Manṣūr b. Muḥammad al-Isfizārī (d. 1101), identified by Abattouy and Hassani 
as one of Malikshāh’s officials (p. 34). Interestingly, both al-Isfizārī and his pa-
tron seem to have been natives of the city of Isfīzār, in Khurasan, and this might 
explain their association. This book has been preserved in a single incomplete 
manuscript (Damascus NL 4460) which contains the theoretical part of the book 
on the subjects of the centres of gravity, the law of the lever, and several causes 
of equilibrium. This text is translated into English (pp. 53-70) and analysed in 
detail by Abattouy and al-Hassani (pp. 89-109). The main sources used by al-
Isfizārī are the Maqāla fī l-mīzān ascribed to Euclid and Thābit ibn Qurra’s Kitāb 
fī l-qarasṭūn; he faithfully reproduces the contents of the original texts and tries 
to improve them, probably with the purpose of making them more accessible for 
his students and easier to understand. As he says in the prologue (p. 55), his book 
contains “what I have learned from the sciences of the Ancients and their wise 
successors, in addition to my own thoughts and that which was deduced from 
demonstrations”. In fact, his methodology is clearly Euclidean: he begins with six 
axioms (mabādi’) related to centres of gravity – which do not need to be proved 
– and a series of examples which clarify the aforementioned principles (pp. 56-
61). This is followed by a series of seven propositions or theorems, accompanied 
by the corresponding geometrical demonstrations. These propositions constitute 
16486_Suhayl.indd   368 20/11/17   11:42
369
The corpus of al-Isfizārī
al-Isfizārī’s analysis of the law of the lever, and the first six are reworkings of the 
corresponding ones in pseudo-Euclid’s Maqāla fī l-mīzān (pp. 61-68), while the 
seventh (pp. 68-70) derives from Thābit’s Kitāb fī l-qarasṭūn. Interestingly, in 
propositions 1-6 the beam of the balance is considered to be a line, with neither 
width nor weight, while in his analysis of proposition 7 al-Isfizārī clearly states 
that the beam is a heavy object.
The contents of the Damascus manuscript end here but, fortunately, the rest of 
al-Isfizārī’s book has been preserved in the second book of al-Khāzinī’s Mīzān 
al-ḥikma, in a passage entitled Fī marākiz al-athqāl wa-ṣan‘at al-qaffān li 
l-Muẓaffar al-Isfizārī (“On the centres of gravity and the making of the steelyard 
by al-Muẓaffar al-Isfizārī”). This text, translated on pp. 71-87, is divided into four 
chapters of which the first two deal with the theoretical part of al-Isfizārī’s origi-
nal work, without the geometrical demonstrations, while chapters 3 and 4 are 
purely practical. Chapter 3 describes how to make a steelyard, a balance with 
unequal arms, and how to weigh with it. Chapter 4, finally, deals with a set of 
common practical problems, such as converting a marked steelyard from one 
weighing system to another, since weights have different capacities in different 
geographical areas; calculating the complementary weight and subtracting it from 
the measured weight; replacement of lost parts and, finally, how to weigh when the 
weight of the load goes beyond the last mark on the steelyard.
The rest of the book is related to the ‘ilm al-ḥiyal (science of the mechanics of 
machines). Al-Isfizārī wrote a book without a title (which Abattouy and Hassani 
call Majmū‘ fī l-ḥiyal, codex of ḥiyal) preserved in two Arabic manuscripts (Os-
mania University Library in Hyderabad QC620/HJ and John Rylands Library in 
Manchester 351). In it he summarized the description of a collection of machines 
extracted from the following authors (in the order in which they appear in the 
text): the Banū Mūsā (9th c., pp. 113-191), Philon of Byzantium (ca. 280 BC - ca. 
220 BC, pp. 193-230), Heron of Alexandria (1st c. AD, pp. 231-248), Apollonius 
of Perga (fl. ca. 262-190, pp. 271-275), and a brief text on the clock box (ṣundūq 
al-sā‘āt) containing only two paragraphs which describe a kind of clock with 
automats. Interestingly, the second paragraph is a condensed description of a hy-
draulic organ known through the longer text of Mūrisṭus (pp. 277-280).
The purpose of the codex of ḥiyal, as stated in the introduction, is to assemble 
“what has reached us from the books of the Ancients about different machines, 
and those who came after them until our era...We reproduced these devices in a 
concise style and with appropriate illustrations, as we found the previous copiers 
had misrepresented the illustrations and introduced many alterations in the letters 
16486_Suhayl.indd   369 20/11/17   11:42
370
Julio Samsó
representing the intent of the authors... We also pointed out their causes in some 
cases” (p. 113). The technique used by al-Isfizārī is that of the epitome, which 
involves rewriting the original text in a condensed form (see p. 45), as well as 
redrawing the faulty figures which have reached him in poorly copied manu-
scripts. This latter task has been repeated by Abattouy and Hassani who present 
the figures (which accompany their translation), both in a reconstructed modern 
form and in a reproduction of the ones that appear in the manuscripts.
The codex contains the whole set of the 100 devices described in the Banū 
Mūsā’s well-known Kitāb al-ḥiyal (edited by Aḥmad Yūsuf al-Ḥasan and trans-
lated by Donald R. Hill) of which 73 are trick vessels for dispending liquids, 15 
are automatic control systems, 7 water jets, 3 oil lamps, a bellows and a mechan-
ical grab for excavating in the beds of streams. Philon of Byzantium’s original 
Pneumatics describes 78 mechanical constructions operated by hot air or steam 
but only 52 of them appear in al-Isfizārī’s collection. This is followed by a sum-
mary, with commentaries, of the first two books of Heron of Alexandria’s Mechan-
ics, which deal with raising heavy objects, centres of gravity and an analysis of the 
five simple machines and their use, singly or in combination: axle (al-miḥwar), 
lever (al-mukhl), pulley (al-bakara), wedge (al-isfīn) and screw (al-lawlab). The 
most interesting part of the collection is, no doubt, the summary of Apollonius’ 
Kitāb al-bakara, a previously unknown work (not extant in Greek or in any trans-
lation) of the famous Greek mathematician author of the Conics. It contains a 
collection of seven demonstrated propositions with diagrams, five of which deal 
with the basic properties of cogwheels.
In the codex of ḥiyal, we obviously have an excellent collection of Greek 
sources on applied mechanics, of which the only important text missing is Pap-
pus’ Mechanics, while the Islamic contribution is represented by the book of the 
Banū Mūsā. Al-Isfizārī’s work is a clear example of the assimilation and, in A.I. 
Sabra’s words, the “appropriation” of the Greek heritage, which was well under-
stood by our author; he was able to summarize, comment upon and correct the 
faulty illustrations transmitted by the successive copies of the original source. 
Like the Irshād, the codex on ḥiyal seems to be a kind of handbook prepared by 
al-Isfizārī for the benefit of his students (pp. 32,109).
Abattouy and Hassani’s book is completed by an extremely useful Arabic-
English glossary of technical terms, accompanied by commentaries (pp. 283-
298), and by five appendices dealing with 1) a list of the manuscripts of the 
Irshād, the Mīzān al-ḥikma, and the Arabic books of the Banū Mūsā, Philon, 
Heron, Apollonius, the pseudo-Euclid and the short text on the ṣundūq al-sā‘āt 
16486_Suhayl.indd   370 20/11/17   11:42
371
The corpus of al-Isfizārī
(pp. 301-302); 2) a list of illustrations taken from the manuscripts (pp. 303-308); 
3) four historical notes with information about the biobibliography of Philon, Her-
on, Apollonius and the Banū Mūsā (pp. 309-326); 4) tables of concordance be-
tween “the paragraphs, models or devices, and figures in the original texts of Banū 
Mūsā, Philon and Heron and their counterparts in the al-Isfizārī Codex of Ḥiyal” 
(pp. 327-334); and 5) sample pages of the manuscripts of al-Isfizārī and al-Khāzinī 
(pp. 335-383). The volume ends with a bibliography divided into a) Arabic pri-
mary and secondary sources and b) publications in other languages (pp. 385-
395), and with an alphabetical index (pp. 397-399).
To sum up, the authors of this volume have made a great contribution to the 
history of theoretical and applied mechanics in the Islamic lands and provide a 
comprehensive study of a little known scientist of the second half of the 11th cen-
tury. Their reconstruction and analysis of the contents of the Irshād can be con-
sidered exemplary and the only absence I can find is the lack of a commentary on 
the texts of the codex of ḥiyal, something acknowledged by the authors them-
selves in the title of the book to which they have added the subtitle “English 
translation, partial analysis and historical context”. This is, however, a very small 
defect in such an important book.
Julio Samsó
16486_Suhayl.indd   371 20/11/17   11:42


Mohammed Abattouy and Salim al-Hassani, The corpus of al-Isfizārī

http://www.raco.cat/index.php/Suhayl/article/download/330042/420788

Mohammed Abattouy and Salim al-Hassani, The corpus of al-Isfizārī

Abstract

Similar works

Full text

Available Versions

Revistes Catalanes amb Accés Obert