Pathfinders
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25. A map from the Book of Routes and Provinces, composed by Abu Ishaq Ibrahim al-Istakhri, showing Iraq, the Tigris river, Kufa, Baghdad and Persian Gulf.
26. The Banū Mūsa brothers’ self-trimming lamp, as described in their Book of Ingenious Devices.
27. The famous Elephant Clock of al-Jazari.
28. The inner workings of the Elephant Clock.
29. Diagram of a system for pumping water into a basin, from the Book of Knowledge of Ingenious Mechanical Devices, by al-Jazari, 1206.
30. Photo of al-Birūni’s mountain from which he measured the circumference of the earth.
31. The newly opened campus of King Abdullah University of Science and Technology (KAUST), in Jeddah.
Notes
CHAPTER 1. A DREAM OF ARISTOTLE
1. Anthony Cutler, ‘Gifts and Gift Exchange as Aspects of the Byzantine, Arab, and Related Economies’, Dumbarton Oaks Papers, 55 (2001), p. 260.
2. Michael F. Hendy, Studies in the Byzantine Monetary Economy c. 300–1450 (Cambridge University Press, 2008).
3. The silver dirham was an Islamic coin, and is a unit of currency still used in several Arab countries today, worth less than the gold dinar.
4. While there is no record of any census, a number of medieval Arab writers had attempted to make crude estimates of Baghdad’s population. They would typically look at factors such as the consumption of foodstuffs, the numbers of people with specialized occupations or the number of houses and mosques. They would then choose what they subjectively felt were sensible multipliers to extrapolate these numbers. At the most ridiculous extreme is an estimate of 96 million, attributed to an eleventh-century Baghdadi writer by the name of Hilāl al-Sābi’, who calculated Baghdad’s peak population based on the number of bathhouses in the city. Conservative estimates, comparing Baghdad in size to Constantinople, which had a population of at least 150,000, means Baghdad would have been home to around half a million inhabitants (see Jacob Lassner, ‘Massignon and Baghdad: The Complexities of Growth in an Imperial City’, Journal of the Economic and Social History of the Orient, 9/1–2 (1966), pp. 1–27). However, many historians argue that Baghdad was the world’s first city with a population of a million.
5. The most famous of the early Abbāsid structures still surviving is undoubtedly the great mosque of Sāmarra north of Baghdad. Built in 851, this 50-metre-high iconic structure with its distinctive spiralling cone minaret (malwiyya) was part of what was once the largest mosque in the world. The few surviving Abbāsid buildings in Baghdad itself are from later periods, such as the Nasiriyya Palace (known today simply as the Abbāsid Palace) built by the Caliph al-Nāsir (r. 1180–1225) and the Mustansiriyya school built during the reign of al-Mustansir (r. 1226–42). Both these caliphs lived during a time when the Abbāsids, and Baghdad, briefly regained their early glories during the period between the occupations of the Seljuks and the Mongols.
6. Michael Cooperson, Al-Ma’mūn (OneWorld, 2005), p. 21.
7. Tayeb El-Hibri, ‘Harūn al-Rashīd and the Mecca Protocol of 802: A Plan for Division or Succession?’, International Journal of Middle East Studies, 24/3 (1992), pp. 461–80.
8. This may not be the real reason for the execution of Ja’far al-Barmaki. One account claims that Ja’far had slept with al-Rashīd’s sister and, although the caliph had agreed that they could marry, it had been on the condition that the marriage was never consummated. Yet another reason may have been simply al-Rashīd’s jealousy of the power and wealth that the Barmaki family had amassed.
9. Michael Cooperson, ‘Baghdad in Rhetoric and Narrative’, Muqarnas, 13 (1996), p. 99.
10. Sunni and Shi’a are the two major denominations of Islam. Sunnis make up the much larger fraction within the Islamic world whereas Shi’a form the majority of the population in Iran, Iraq, Lebanon, Bahrain and Azerbaijan. The historic background of the Sunni–Shi’a split can be traced back to the schism that took place after the Prophet Muhammad died in the year 632, leading to a dispute over succession, particularly surrounding the rights of Ali ibn abi Tālib, the fourth caliph and son-in-law of the Prophet. Over the years Sunni–Shi’a relations have been marked by both cooperation and conflict, with conflict predominating, most recently in Iraq following the overthrow of Saddam.
11. Dimitri Gutas, Greek Thought, Arabic Culture (Routledge, 1998), p. 98.
CHAPTER 2. THE RISE OF ISLAM
1. A good discussion can be found in Albert Hourani’s excellent A History of the Arab Peoples (Faber and Faber, 2005), pp. 12–14.
2. Historians cannot agree on whether or not Mecca was actually called Macoraba in ancient times. The name is mentioned in the writings of the Alexandrian astronomer and geographer Ptolemy, in the second century CE. According to Islamic tradition, the Ka’ba (the holiest of all Muslim shrines) is supposed to have been built by the prophet Abraham around 2000 BCE. As for Yathrib (Medina), its first documented mention is in Assyrian texts dating back to the sixth century BCE. Ptolemy refers to it in his writings as Lathrippa.
3. Non-Arabs who converted to Islam, such as Egyptians, Persians and Turks, were known as Mawāli.
4. The Abbāsid dynasty is often mistakenly believed to be named after its first caliph, Abū al-Abbās. In fact, it refers to an uncle of the Prophet by the name of al-Abbās. The caliph with the similar name was the head of a branch of the Banū Hāshim tribe, who trace their lineage to the great-grandfather of the Prophet, via al-Abbās.
5. R. Coke, Baghdad: The City of Peace (Thornton Butterworth Ltd., London, 1927), p. 32.
6. Al-Tabari, The Early Abbāsi Empire, trans. J. A. William, 2 vols., vol. 1: The Reign of Abū Ja’far al-Mansūr AD 754–775 (Cambridge University Press, 1998), p. 145.
7. Jacob Lassner, ‘Massignon and Baghdad: The Complexities of Growth in an Imperial City’, Journal of the Economic and Social History of the Orient, 9/1–2, (1966), p. 6.
CHAPTER 3. TRANSLATION
1. Dimitri Gutas, Greek Thought, Arabic Culture (Routledge, 1998), p. 2.
2. It is important to note that translations from Pahlavi into Arabic did in fact take place decades before the arrival of the Abbāsids, but these were few and far between and mostly dealt with administrative matters such as Sasanian financial and tax records for the Umayyads. (See, for instance, M. Sprengling, ‘From Persian to Arabic’, American Journal of Semitic Languages and Literatures, 56/2 (1939), pp. 175–224.)
3. Michael Cooperson, Al-Ma’mūn (OneWorld, 2005), p. 32.
4. David Pingree, ‘Classical and Byzantine Astrology in Sasanian Persia’, Dumbarton Oaks Papers, 43 (1989), pp. 227–39.
5. David Pingree, ‘The Fragments of the Works of Al-Fazārī’, Journal of Near Eastern Studies, 29/2 (April 1970), pp. 103–23.
6. The importance of geometry in engineering is best exemplified by the Arabic word handasa, which to this day means both ‘geometry’ and ‘engineering’.
7. Martin Levey, ‘Mediaeval Arabic Bookmaking and its Relation to Early Chemistry and Pharmacology’, Transactions of the American Philosophical Society, new series, 52/4 (1962), pp. 1–79.
8. This is certainly what is claimed in De Lacy O’Leary’s How Greek Science Passed on to the Arabs (Routledge & Kegan Paul, 1949), pp. 104–9, but is a view not by any means universally accepted today.
9. The astrolabe is an ancient astronomical device invented by the Greeks, typically made of brass and the size of small plate, although much larger and smaller ones were made. It was used by astronomers, navigators and astrologers for solving problems relating to the position and motion of the heavenly bodies across the sky. By far the most popular type was the planispheric astrolabe, on which the celestial sphere is projected onto the plane of the equator. To use one, the moveable components are adjusted to a specific date and time. Once set, the entire sky, both visible and invisible, is represented on the face of the instrument.
A typical astrolabe has a circular plate, referred to as the mater, with a central peg on to which a set of smaller rem
ovable disks (the tympans) are placed. Each of these is made for a specific latitude and engraved with what is called a stereographic projection of a portion of the sky, which involves mapping points of a sphere on to a two-dimensional surface retaining their angular distribution. Angles are marked out around the rim of the mater. Next, sitting above the uppermost tympan is a rotating framework, called the rete, which is essentially a reference star chart that has engraved on it some of the most important constellations in the sky that are matched with the stars on the tympan below it. Above this is a pointer that also pivots around the central peg, which is marked with a scale showing angles of latitude in the sky.
On the other side of the astrolabe is a sighting arm, or alidade, which is used to make a reading of the angle of inclination of the object being viewed in the sky when the astrolabe is hung vertically.
10. Al-Mansūr’s interest in Euclid’s Elements is mentioned in the great work of the fourteenth-century historian Ibn Khaldūn (1332–1406), Al-Muqaddima (An Introduction to History), trans. Franz Rosenthal (Princeton University Press, 2005), p. 374.
CHAPTER 4. THE LONELY ALCHEMIST
1. Henceforth, since this is how I write my own name, I will depart from the more ‘correct’ way of writing an Arabic family name with a lower-case letter ‘a’ in the definite article.
2. Not to be confused with Euclid’s mathematical text the Elements, an element in chemistry is defined as a substance that cannot be decomposed into a simpler one by chemical means. We now know that there are more than 100 elements that make up all matter, some of which are created artificially and are highly unstable.
3. W. R. Newman and L. M. Principe, ‘Alchemy versus Chemistry: The Etymological Origins of a Historiographic Mistake’, Early Science and Medicine, 3/1 (1998), pp. 32–65.
4. Quoted in S. E. Al-Djazairi, The Golden Age and Decline of Islamic Civilisation (Bayt Al-Hikma Press, Manchester, 2006), p. 320.
5. Quoted in E. J. Holmyard, Makers of Chemistry (Clarendon Press, 1931), p. 60.
6. Bayard Dodge (ed. and trans.), The Fihrist of al-Nadīm (Columbia University Press, 1970), vol. 2, p. 855.
7. Newman and Principe, ‘Alchemy versus Chemistry’, p. 38.
8. Ibid., p. 40.
9. See, for instance, the discussion about al-Kindi in Lynn Thorndike, Arabic Occult Science of the Ninth Century, (Kessinger Publishing, 2005), an extract from the same author’s History of Magic and Experimental Science, vol. 1 (Columbia University Press, 1923).
10. This is a little unfair as some Greek scholars, such as Archimedes and Hipparchus, were certainly careful experimentalists.
11. In W. R. Newman, The ‘Summa Perfectionis’ of Pseudo-Geber: A Critical Edition, Translation and Study, Collection de Travaux de l’Académie Internationale d’Histoire des Sciences, 35 (Brill, annotated edn., 1997).
12. J. M. Stillman, ‘Falsifications in the History of Early Chemistry’, Scientific Monthly, 14/6 (1922), pp. 560–67.
13. E. J. Holmyard, ‘A Critical Examination of Berthelot’s Work upon Arabic Chemistry’, Isis, 6/4 (1924), pp. 479–99.
14. S. N. Haq, Names, Natures and Things: The Alchemist Jābir ibn Hayyān and his Book of Stones (Kluwer Academic Publishers, 1994), p. 11.
15. P. Lory, L’Élaboration de l’Élixir Suprême: Quatorze traités de Gābir ibn Hayyān sur le œuvre alchimique (Bibliothèque Damas: Institut Français de Damas; Maisonneuve, Paris, 1988).
16. Haq, Names, Natures and Things, p. 25.
17. J. R. Partington, A History of Greek Fire and Gunpowder (Johns Hopkins University Press, 1998), p. 307.
18. V. Karpenko and J. A. Norris, ‘Vitriol in the History of Chemistry’, Chemické Listy, 96 (2002), pp. 997–1005.
19. E. J. Holmyard, Alchemy (Penguin, 1957; repr. Dover Publications, 1991), p. 81; C. Singer, The Earliest Chemical Industry (Folio Society, 1958), p. 61.
20. Holmyard, Alchemy, p. 139.
CHAPTER 5. THE HOUSE OF WISDOM
1. Michael Cooperson, Al-Ma’mūn (OneWorld, 2005), p. 81.
2. See, for instance, Dimitri Gutas, Greek Thought, Arabic Culture (Routledge, 1998), p. 53, or George Makdisi, The Rise of Colleges: Institutions of Learning in Islam and the West (Edinburgh University Press, 1981), p. 26.
3. Gutas, Greek Thought, Arabic Culture, p. 54.
4. S. E. Al-Djazairi, The Golden Age and Decline of Islamic Civilisation (Bayt Al-Hikma Press, Manchester, 2006), p. 187; Y. Eche, Les Bibliothèques arabes (Institut Français de Damas, Damascus, 1967), p. 11.
5. There are two accounts of this man, one from the historian al-Nadīm (Bayard Dodge (ed. and trans.), The Fihrist of al-Nadīm (Columbia University Press, 1970), vol. 2, p. 639) and the other by the Baghdadi scholar al-Jahith, a contemporary of al-Ma’mūn (A. F. L. Beeston (trans.), ‘On the Difference between Enmity and Envy, by al-Jāhiz’, Journal of Arabic Literature, 18 (1987), p. 31).
6. Gutas, Greek Thought, Arabic Culture, p. 57, and George Sarton, Introduction to the History of Science, vol. 1 (Carnegie Institution of Washington, 1927), p. 531.
7. Dodge (ed. and trans.), The Fihrist of al-Nadīm, vol. 2, p. 584.
8. Ibid., p. 19.
9. It is worth mentioning that Ishāq is the Arabic version of the name Isaac and is pronounced with the ‘s’ and ‘h’ separated (iss-hāq).
10. Sarton, Introduction to the History of Science, vol. 1. Worth noting also is that this ‘Time of al-Khwārizmi’ is sandwiched between those of the two great contributors to the discipline of chemistry: the previous half century (750–800 CE) is referred to as ‘The Time of Jābir ibn Hayyān’, and the second half of the ninth century as ‘The Time of al-Rāzi’.
11. Obviously, Muhammad ibn Mūsa knew nothing of the gravitational force of attraction between bodies, let alone its mathematical proportionality to the inverse square of the distance between them. His brilliance was in providing an early glimpse at the universality of the laws of nature, applying as they do to both earthly and heavenly bodies.
12. Teun Koetsier, ‘On the Prehistory of Programmable Machines: Musical Automata, Looms, Calculators’, Mechanism and Machine Theory, 36 (2001), pp. 589–603.
13. M. Mayerhof, ‘New Light on Hunayn ibn Ishāq and his Period’, Isis, 8/4 (1926), pp. 685–724.
14. Peter E. Pormann and Emilie Savage-Smith, Medieval Islamic Medicine (Edinburgh University Press, 2007), p. 65.
15. Al-Jahiz, Kitab al-Haywān, vol. 4 (Al-Matba’ah al-Hamīdīyah al-Misrīyah, Cairo, 1909), p. 23 (in Arabic).
16. Ibid., p. 24.
17. Ibid., p. 25.
CHAPTER 6. BIG SCIENCE
1. Hugh Thurston, ‘Greek Mathematical Astronomy Reconsidered’, Isis, 93/1 (2002), pp. 58–69.
2. Sonja Brentjes, in Thomas Hockey (ed.), The Biographical Encyclopedia of Astronomers (Springer, 2007), p. 1011.
3. Benno van Dalen, in Hockey (ed.), The Biographical Encyclopedia of Astronomers, pp. 1249–50.
4. e.g., E. S. Kennedy, ‘A Survey of Islamic Astronomical Tables’, Transactions of the American Philosophical Society, new series, 46/2 (1956), pp. 123–77.
5. Gregg DeYoung, in Hockey (ed.), The Biographical Encyclopedia of Astronomers, p. 357. On the issue of the theory of astrolabe construction, two later astronomers, al-Battāni and al-Bīrūni, would develop the mathematics considerably further than al-Farghāni.
6. It is well established that the word zīj, like a number of other technical terms, came from the Persian and originally meant a thread. It came to stand for the set of parallel threads making up the warp of a fabric and later to mean a table of numbers because of the resemblance between the closely drawn vertical lines of a numerical table and the warp set up in a loom. It finally came to denote whole sets of astronomical tables, which is the meaning here.
7. Marvin Bolt, in Hockey (ed.), The Biographical Encyclopedia of Astronomers, p. 740.
8. T. F. Glick, S. Livesey, F. Wallis (eds.), Medieval Science, Technology and Medicine: An Encyclopaedia, Routledge Encyclopaedi
as of the Middle Ages (Routledge, 2005), p. 64. See also Aydin Sayili, The Observatory in Islam and its Place in the General History of the Observatory, Publications of the Turkish Historical Society, 7/38 (Ayer Co. Pub., Ankara, 1988).
9. Quoted in David Woodward, ‘The Image of the Spherical Earth’, Perspecta, 25 (1989), p. 3.
10. Thurston, ‘Greek Mathematical Astronomy Reconsidered’, p. 66.
11. Posidonius had carried out his own measurements following Eratosthenes’ method and agreed with his value of 250,000 stadia to begin with but then revised it downwards to 180,000, which is the value Ptolemy quotes.
12. Sonja Brentjes, in Hockey (ed.), The Biographical Encyclopedia of Astronomers, p. 1011.
13. Mas’ūdi, from The Meadows of Gold, trans. P. Lunde and C. Stone (Penguin, 2007), p. 48.
14. Michael Cooperson, Al-Ma’mūn (OneWorld, 2005), pp. 2–3.
CHAPTER 7. NUMBERS
1. R. L. Goodstein, ‘The Arabic Numerals, Numbers and the Definition of Counting’, Mathematical Gazette, 40/332 (1956), pp. 114–29.
2. It was also independently known to the Chinese, as the Gou Gu theorem, and to the Indians as the Bakhshali theorem.
3. It is most likely that the Indian iterative algorithm for computing square roots is based on an earlier Babylonian one, however.
4. Otto Neugebauer, The Exact Sciences in Antiquity (Brown University Press, 1957; Dover, 1969), p. 46.
5. J. D. Buddhue, ‘The Origin of our Numerals’, Scientific Monthly, 52/3 (1941), pp. 265–7.
6. D. E. Smith and L. C. Karpinski, The Hindu-Arabic Numerals (Ginn and Co., 1911).