[In the following essay, originally presented as a lecture to the Iran Society, Barani surveys the major scientific accomplishments of al-Bīrūnī and provides a brief biography.]

I feel most honoured by the privilege so very kindly bestowed on me to deliver a short lecture on the Scientific Achievements of Al-Bīrūnī on this memorable occasion when we have all collected here to celebrate the Millenary of the great savant and scholar under the auspices of the Iran Society, which has recently published an excellent Commemoration Volume, and under the presidentship of your illustrious Governor, whose personal interest in the celebrations should by itself be a significant guarantee for their success. It is also in the fitness of things that Calcutta should be the venue, for in the modern India it has always been in the forefront of our intellectual life, and recently also served as the standard-bearer in the march of Al-Bīrūnīan studies.

When on behalf of the Society I was invited by my friends, the President and the Secretary, to come and address you, the idea, so welcome in other respects, e.g., the precious opportunity of meeting the intellectual elite of Calcutta and other places, was, let me confess to you, almost terrifying. For although my attachment to Al-Bīrūnī as his biographer and admirer appears to be mainly responsible for the choice, I have never deemed myself fully equipped to deal with the Scientific Achievements of such a many-sided genius. In such matters the biographer and historian's role is usually very much lightened by the results obtained in their respective fields by the historical researches of the specialists, and all that is generally required of the former is to bring those researches together to the door of the general reader in a lucid, connected and attractive form, rather than to launch on the hazardous task of the original researches in so many different subjects, with most of which he may have only a nodding acquaintance; more so where the East is concerned, when he has also to get over the double hurdle of the languages and ideas, and in the case of Al-Bīrūnī, also over a still more perilous hurdle of traversing across the most varied areas of nearly all the Sciences and learning of his time and showing their bearing on our modern knowledge.

You have no doubt heard of the great Arab Renaissance of Learning from the 8th to the 13th centuries, connecting link between the Antiquity and the Modern times, which Renaissance had reached its peak, in the 10th and 11th centuries A.D., and the 4th and 5th of the Hegira, and wherein Iran of those days played the most leading part. In that vast Himalayan range of learning Al-Bīrūnī stands out like the Mount Everest peak. I, therefore, honestly believe that it should yet be the task of the organised labour of so many for many more years to come, before anything like justice could be done to the master's work.

What I, therefore, propose to do just now is to fix a few sign-posts, indicating fertile lands, spread in all directions for those seeking to traverse them, and also cite a few instances which will give some idea of Al-Biruni's Scientific Achievements, and to leave the whole paraphernalia of the texts, authorities and other details for the notes, which could conveniently be added later on.

Al-Biruni was a born Scientist in the sense in which you talk of a born Poet, Artist or Philosopher. Taking all the knowledge and learning of his time into his province, and making considerable part of it his own, and embellishing all the rest that he found time to touch, his outlook, temper and method were strictly Scientific. In his later years he still claimed himself to belong to a single branch of Mathematics, i.e., Astronomy, to which, he says, he had devoted himself from childhood.² It must have been merest modesty on his part to say so, for we all bear witness to the fact that besides his main subject he commanded an almost encyclopaedic range of learning. One could very well deal with him as a mere Literateur,³ for he was a poet and prose-writer of distinction; or as a Philologist,⁴ for besides the languages of his own land and religion he had mastered Sanskrit, from which and into which he could translate Scientific and Philosophical works, and knew something of Hebrew and Syrian, and a little of Greek, on which he could depend for his purposes; or as a Historian,⁵ for we know the names of his historical works, including a history of Mahmud and his father, the loss of which is regrettable; or as a Sociologist⁶ with wide interests in Archaeology, Anthropology, Comparative Religion, Culture, Manners and Morals; or even as a Philosopher, although Muslim historians were not inclined to take him as such in the sense in which they held his great contemporary Ibni Sina, who had specialised and left a complete encyclopaedia on it.

My life-long study of his available works has led me to believe that, like Ariotele, in the various parts of Al-Biruni's life some special subjects kept him more attracted than others,⁷ and he never ceased to attach a new trophy every time as he advanced from Science to Science to the end of his life of more than 80 years.⁸

Born in a small suburban village of Khwarizm in 362 A.H. (973 A.D.) of insignificant and almost unknown family, and most probably orphaned at a very early age, he was brought up, and trained by a most distinguished Mathematician and Astronomer, Abû Nasr Marsû, who belonged to the reigning family of Khwarizm, a meeting place of the Eastern and Western cultures of those days, and was most probably of Persian extraction, although the Turks so vehemently claim him with Ibni Sina and Al-Farabi to be of Turkish origins. The purity of races was perhaps never so much ensured in that land lying between the homelands of the Mongols and the Aryans. Coming almost at the crest of that intellectual wave that had swept from end to end over the Muslim world after the impetus given to it by the earlier Abbasids, of whom the names of Al-Mansûr Al-Hârûn and Al-Mâmun are so well known, he is the third in the golden chain of the Persian Mathematicians and Astronomers beginning with the well-known Abu'l-Wafâ of Bfizjan, the acknowledged teacher of Abu Nasr Mansur, Al-Bīrūnī's own patron and master—a fact which is not yet so well known.⁹

While only about 18 Al-Bīrūnī had begun to make researches at his own Observatory in an insignificant mountain village in his land, trying later on to bring them into line with the Solar observations that were being simultaneously carried on by Abu'l-Wafâ at Baghdad.¹⁰ After several years his whole work at the Observatory was frustrated by the internal war, leading to the extinction of the ancient rulers of the land, though his teacher Abfu Nasr survived. And for several years Al-Biruni was in exile, wandering in the Northern Iran and the neighbouring kingdom of Jujân, where reigned Qâbûs, himself an author and literateur and lover of Science, who was so much enamoured of Al-Biruni that he would fain share ruling power with the latter.¹¹ But the discerning eyes of the scholar saw in him the bloody tyrant that he was,¹² and led him to return to his own country to the fold of the more enlightened and humane rulers and to carry on his labours for about another decade or so, and also be the trusted adviser and minister¹³ to the throne. This time he established an Observatory in the royal palace, and was once more busy in the Astronomical and Geographical researches, when the work was again frustrated by another bloody revolution soon followed by Mahmud's invasion and annexation of Khwarizm in 408 A.H. (1017 A.D.). Thus closed the first chapter of his life at the age of 46; to begin the more fruitful second of it.

For his activities during the earliest part of his life Kitab Al-Âthâru'l-Bâqiah written for Qâbûs in 390 A.H., i.e. about 1,000 A.D., is a significant index. And we know what a range of scientific interest that work discloses. His predominant interest in it is Mathematical, Astronomical and Historical, the subject-matter being a comparative study of all the ancient and current Calendars known to him, but his superabundant knowledge overflows the limits.¹⁴ As the text and English translation are well known and have been drawn upon by several scholars, and a good Persian translation is also in print, we need not expatiate on it.

Another interesting piece of work from these times is a collection of letters¹⁵ exchanged still earlier between himself and his younger contemporary Ibn-i Sînâ before both came together at the Amir of Khwarizm's court towards the end of the 4th century A.H. Here Al-Biruni poses an amazing string of searching questions, mostly directed against the orthodox Aristotlian science—e.g. the possibility of the revolution of the planetary spheres in the elliptic courses, saying that there was no justification why Aristotle's idea of revolution in complete circle be taken as conclusive and final. Others relate to the Atomic Theory discredited by Aristotle; the existence of other Universes, so vehemently denied by Aristotle; the nature of changes caused by the mixing of the elements of matter and the nature of sight, where too Aristotle had gone astray. Throughout you mark his independence of mind and vision for right views. Again and again we find him here as elsewhere trying to free the human intellect from the bonds set on it by the intellect of the great Greek master much in contrast against the mental attitude of some other great thinkers like Ibn-i Rushd (Averroes) Ibnu'l-Haitham and Ibn-i Sînâ (Avicenna), who were certainly more attached to Aristotle, though certainly not all of them as mere camp followers. I take liberty to quote here an interesting passage from another later work of Al-Biruni:—

And the trouble with these people is their extravagance in respect of Aristotle's opinions, believing that there is no possibility of mistakes in his views, though they know that he was only theorizing to the best of his capacity, and never claimed to be God's protected and immune from mistakes. (His book on the Celestial Phenomena is full of errors.)¹⁶

But in a much later work, of which there exists in Istanbul possibly in Al-Biruni's own hand the unique copy of 416 A.H.,¹⁷ references to his labours during all these years abound; and it should serve as a rich mine of information when the entire text is faithfully reproduced in photographs.

It appears that subsequent to the study of Calendars he was very much interested in the Astronomical and Physical Geography, and prepared a Hemisphere of the diameter of about 15 feet covered with a net of longitudes and latitudes, and whereupon he used to locate the important places, of which he had fixed exact situations from oral and documentary sources, or by his own personal observations.

When taken to Ghaznah he had to leave the Hemisphere behind and also all the data so laboriously collected by him, though he still hoped and pined to recover them by turn in fortune and eventually to complete the unfinished work.¹⁸

With Al-Biruni's arrival at Ghaznah we see the amplest widening of his Scientific and literary interests. We have now materials enough to controvert Sachau's opinion that Al-Biruni had little direct dealings with Mahmud's court. On the contrary in a rare autobiographical piece of poetry written just after Mahmud's death he counts the latter as his greatest patron,¹⁹ though I do not exclude the possibility that just after his arrival there he was for a very short while detained in the fort of Nandana now in the Western Punjab, where he carried out his researches in Geodesy, of which I have rendered an account in the Al-Biruni Commemoration Volume. When released he was at once admitted into the brilliant court circle as the royal Astrologer, and set up in Ghaznah his third Observatory, wherein in the years 409, 410 and 411 A.H. he revived his former Astronomical researches and fixed the longitude and latitude of the Metropolis. For the same purpose at great peril to himself he visited Kabul²⁰; and during his travels in the Western part of India he took care to fix some places of which he has left a record in the Indica. A complete table for the entire World fortunately now in print forms an important part of Al-Qânûn.²¹ For how many years he continued his work at the Ghaznah Observatory, and what actual newer results he obtained there, could be discussed only after a thorough study of his opus magnum. It is to the new independent states of India and Pakistan as well as to the Soviet Central Asia, Iran and Afghanistan that my mind naturally turns as those best entitled to undertake it, but above all to our own Republic of India where I am sure we can count on the sympathy and support of such enlightened, learned and discerning minds as our President, Premier and Education Minister happen to possess.²²

It appears that during these years his one main preoccupation was to determine the Obliquity of the Ecliptic, one of the most important problems of the ancient Astronomy. A number of previous Muslim observations from Al-Mâmûn's times onward had distinctly varied within a very short range from the Indian and Greek observations; and in order to be sure Al-Biruni devoted off and on more than 30 years from 380 A.H. to 411 A.H. at his three different observations and found it as 23°-35′ as against 23°-51′-20″ of the later Greeks and 23°-54′ of the Chinese and 24° of the ancient Greek and Indian astronomers. Evidently the angle of this Obliquity had been progressively decreasing. But Al-Bīrūnī failed to discover it.²³

Still much earlier the problem of the Spherical Projection and its application to Map-making had engrossed his attention, and in his Al-Âthâr he claims original devices of his own—a subject very well discussed by the Iranian scholars Sairafī and Deh-Khudâ, showing that he had anticipated Mercater and others in this matter. Even much towards the end of his life he was still busy in perfecting and applying his methods to actual maps, as some titles of his works show. It is in Ghaznah that the idea of the Indian studies and thereby serving both the nations dawned on Al-Biruni's mind. I am not yet sure of the chronology of his Indian travels and am awaiting more light from some of his other works that may be discovered in the future; and although his Muslim biographers, impressed by his Indian learning, exaggerated the length of these travels to 40 years, I am inclined to think, from 7 to 10 years must have been mainly devoted to the Indian subjects before he completed his Indica soon after Mahmud's death.²⁴ In an unnoticed passage in Al-Jamâhir I find Al-Bīrūnī saying that he had a talk with Mahmud on the way while the latter was returning from Mathura.²⁵ Apparently Al-Bīrūnī did not himself accompany Mahamud to Mathura, and it must have been somewhere in the Western India or the Eastern Afghanistan. It would be no good on my part to revert to the Indica, that inexhaustible mine of information and constant source of study and research by the scholars of the East and the West. It is, however, amply evident that both in his Indica and Al-Âthâr his interests are mainly Scientific, though not exclusively so.

And now we have before us a very important series of the four Mathematical and Astronomical treatises of Al-Bīrūnī and 15 of his master Abû Nasr Mansûr's all published by the Dâiratu'l-Ma'arif of Hyderabad (Deccan).… Besides some biographical and historical references of general interest you have in them a whole series of the Mathematical solutions which Al-Bīrūnī claims as his own or derived from purely Indian origins altogether unknown to the Muslims of his times; and about which the opinions of the better informed alone could be of much value.

Having rendered account of his Indian researches and carried out translations into Sanskrit and Arabic of some Scientific and Philosophical works he turned his attention to the chiefest field of his studies and took up to give a full and uptodate account of the Astronomical Sciences of his times in Al-Qânûn al-Maśûdū, completed after 427 A.H. And what an advantage he had therein of utilizing, besides his own, all the Indian, Greek and Arab researches up to his times. The story goes that Sultan Maśûd rewarded him for this work with an elephant load of silver, which the great scholar returned with thanks, saying that he needed none of it. This must have been the crowning moment in the master's life. All are agreed that Al-Qânûn is by far the best work of its kind, full of much new information.

In the last years of his life Al-Bīrūnī interested himself in the Medical Science and History, in Mineralogy and Precious Stones, and piled treasures of original material researches in Al-Jamâhir, now in print, and Al-Saidana, only partly so, though a complete copy of it exists at Brusa in Turkey awaiting publications. In Medicine his main interest besides its history was in the Drugs and Medicinal Simples rather than in its theory and practice. Al-Bīrūnī was the first Muslim author to give an account of the Chinese tea;²⁷ though not of the Chinese porcelain.²⁸

In sundry other sciences, e.g. Optics, he had separate works and one of them Lam 'at was cited and drawn upon not long ago in your own Province by the author of the Jamai Bahadur Khâni, wherein are extracted several of Al-Bīrūnī's original theorems.²⁹ If we are ever able to trace this work, it would be most interesting to compare its contents with the original researches of his contemporary Ibnu'l-Haitham, the greatest Arab Optician, the complete Ms. of whose Al-Manâzir, long deemed lost, exists in Istanbul and forms the subject matter of a most valuable detailed study by an Egyptian savant, Mustafâ Nasîf Bak.³⁰

Al-Bīrūnī was interested from the outset in the nature of Light and Sight and actually proposed queries on these subject to Ibn-i Sînâ&,³¹ who with Al-Bīrūnī and Ibnu'l-Haitham believed that the objects themselves emitted rays to the eyes, thereby causing the formation of their images in the eyes.

Al-Bīrūnī also wanted to know whether Light was material or immaterial. Geology had not yet become an independent science. But much in advance in time we have in his Al-Tahdid some observations on the antiquity and gradual development of the Earth through natural causes. The passage is too long and involved for full reproduction here and I only give you a very brief resumé of its first few paragraphs in the following:—

Our World is not eternal, but it is not possible to give its age or date of origin. All that is obvious is that events have succeeded within the unknown and unspecified periods of time. We have neither revelation nor records of history to help us n this matter. Even in the Quran the days of the Creation are meant to be thousand or fifty thousand years long.

We have to go upon the records of the rocks and vestiges of the past to infer that all these changes should have taken place in very very long times and under unknown conditions of cold and heat: for even now it takes long time for water and wind to do their work. And changes have been going on and observed and noticed within the historical times.³²

Then follows that long passage citing specific instances which has been extracted and dealt with by the learned Knenkow in your Commemorative Volume.³³

On Meteorology, on the Scientific Instruments, on Specific Weights, and Weighing Mechanisms, on the Ratio between the Weights of Metals and Jewels, on Meteors and Comets, on Dawn and Sunset, and on Marvels, Prodigies of Nature, and on Solar Spots, you have his separate works.³⁴

Besides new Astrolabes of his own contrivance, he had constructed for the mosque of Ghaznah a special machine for ascertaining the exact times for the Muslim prayers. But the narrow-minded Imâm rejected it as it was based on the Solar system and the Roman months.

Al-Biruni was so much offended that he scrapped the entire machine and remarks that it was foolish to deprive ourselves of the benefits of Scientific knowledge merely because it came from foreigners. The Romans were men just like ourselves and we would not give up walking and eating simply because they also did the same.³⁵

As to Al-Biruni's Scientific outlook much is already known to you of his catholicity of mind and complete freedom from prejudice and fear. He deserves well to be classed as a staunch pacifist in an age so much devoted to military exploits. In a well-known passage in Indica he speaks disparagingly of Mahmud's Indian raids. The same sentiment is apparent in other places in his works.³⁶

Trained from the outset in the exact sciences and hoping to bring all human knowledge to their precision, he is fond of relying on Experience and Experimentation.³⁷ He is impatient with those who in Science are prone to rely on mere authority against evidence to the contrary as also against those who in the name of Religion assail or reject Scientific truths. Otherwise his attitude to Religion is most sympathetic, although not favourable to Mysticism or Esoterism.³⁸ I may be allowed to mention here an interesting fact given by Al-Biruni himself in one of his later works. He says he used to put on a ring with two different types of the same stone separately venerated by the Sunnîs and Shi'as, just to show that he belonged to both of them.³⁹

But even the best human minds have their limitations. He was never able to appreciate Râzî's researches in Chemistry. Alchemy had to him all the appearance of a pseudo-science on account of its search for the Elixir of life and unsatiable greed for gold.' Modern researches, however, go to show that in the hands of the eminent Muslim Physician Râzî it yielded good and great Scientific resultants. After all, the Alchemist's basic theory regarding the change of the Elements was not really such a wild dream, although we had to wait to our own times for its actual Demonstration. On the other hand Al-Biruni's attitude to Astrology was surely not so hostile, though he indicates in [AI] Tafhîm that he did not very much believe in it.⁴¹ But we know for certain that he remained attached to it to the end, even consulted it in his own troubles, and was reputed as the greatest Astrologer.⁴² On the contrary Al-Fârâbî, Ibn-i Sînâ and Ibn-i Rushd had no faith in it.

Similarly, he was surpassed by another contemporary Astronomer Abû Sa'îd of Sistan, who had an idea of the world's Rotation and Revolution and also a premonition of the Gravitational pull. As a well-known passage translated below would show Al-Bīrūnī did not altogether rule out the possibility of the Earth's movements, but for himself he stuck to the end to the Ptolemaic theory and defended it:

I have seen the Astrolabe called Az-Zarqânî, invented by Abú Sa'îd Sijzî. I liked it very much and praised him a great deal, as it is based on the idea entertained by some to the effect that the motion we see is due to the Earth's movement and not to that of the Sky. By my life it is a problem difficult of solution and refutation.…

For it is the same whether you take it that the Earth is in motion or the Sky. For, in both the cases, it does not affect the Astronomical Science. It is just for the Physicist to see if it is possible to refute it.⁴³

Some other Muslim Astronomers of his time and later times succeeded in discovering the fact that the Obliquity of the Ecliptic was progressively decreasing in a regular way;⁴⁴ but Al-Biruni, in spite of his protracted observation and full knowledge of the results of the earlier Astronomers, failed to discover it.

Al-Bīrūnī frankly admits that Arabic and Persian were not his mother tongues. For the Scientific subjects he has a distinct preference for Arabic, though he is quite critical of the system of the Arabic alphabets.⁴⁵ As he advanced in life his style matured to conciseness and brevity, so that in his time he was blamed for obscurity and difficulty. And all of us who have to deal with him in the original texts meet with no little embarrassment. You cannot take away a single word without damaging the sense, but you have to do some reading between the lines, and sometimes elicit references to his life and surroundings to avoid pitfalls, instances of which are not lacking in the existing foreign translations of his works. He himself used to reply to the critics saying that he had written only for those who would dive deep into his writings, but in my opinion probably pressed so constantly as he was by new ideas and plans, he had to resort to economy of language, or maybe his command of Arabic did not equal that of Ibn-i Rushd and Ibnu'l-Haitham, who were born into it. But after making all such allowance we must admit that no other scholar had ever to put Arabic to such a severe test by bringing the entire Indian Sciencés and learning within the Muslim fold and coining hundreds of technical terms for his purposes.

It is, therefore, with a justifiable pride in his life-work that in a rare self-applauding mood he bursts out in poetry saying:—…

By my own efforts I have surpassed the leaders
  of learning
     They have not acquired knowledge as I
       have done;
They have never sat for discussion in so many
 seats of leaning,
    Nor have they ever been taken prisoner
     by the knotty problems as I have been;
And ask my worth from the Hindus in the East,
    And in the West from him who has
     considered the hard fight I had to
      put (for the sake of learning).⁴"

Notes

… ² The preface of Al-Qânûn al-Mas 'ûdî reproduced in the Appendix 1 (pp. 225-234) of my "Life of Al-Bīrūnī" (Urdu), 2nd Edition, Aligarh, 1927.…

³ As has actually been done by Yâqût in his Irshâdu 'lArîb, Vol. VI (pp. 308-314) (Gibb Memorial Edition), & Vol. XVII, pp. 188-194, (Cairo Edition), where he cites Al-Bīrūnī's literary works and also quotes several passages of poetry.

⁴ The range of Al-Bīrūnī as a mere linguist is really very wide. He was fully acquainted with the various Iranian and Turkish dialects of Central Asia. e.g. of Saghd (Bokhara), and would try to learn the words of any other language he came across in his actual life or studies, as is quite apparent from his extant works like al-Âthâr, Al-Jamâhir and A l-Saidanah.

⁵ He wrote the history of his own country Khwarizm, part of which work has been preserved in Persian translation by Baihaqî in his History of Mas 'ûd of Ghaznah's reign, (pp. 836-868, Calcutta Edition), and also of the Shi'ah sects of Qarâmita etc. Al-Âthâr is equally a work of Ancient History. And Al-Bīrūnī's treatment of purely Scientific subjects is always historical and comparative. When dealing with any problem or topic he generally traces its history. Numerous instances can be gleamed from Al-Qânûn, which would serve as a great source-book for our study of the entire history of Mathematical and Astronomical Sciences up to Al-Bīrūnī's times.

⁶ Al-Bīrūnī's interests in the Social Sciences were very extensive, and all his extant works, e.g. Al-Âthâr, Indica dsA Al-Jamâhir, are full of numerous instances The subject is too wide for a cursory treatment here, and would need a complete study.

For instance, his old biographers Al-Baihaqî and Ash-Shahrzûri were not prepared to deem him properly gifted for the Philosophical topics. Evidently these authors accepted Philosophy in its limited sense of purely Metaphysical discussions.

⁷ A complete chronology of his works is yet to be made to throw full light on the gradual development of his studies.

⁸ The ordinarily accepted date for his death on Friday, 2nd Rajab 440 A.H., (11th September, 1048 A.D.) at the age of 77 years 7 months is not now acceptable in view of his clear statement to the effect that he wrote his Al-Saidanah after he was eighty

⁹ A full study of Abû Nasr Mansûr's life and works and Scientific achievements is yet to be made. Nasiru'd-Din Tûssi, who based his treatise on Menelaus' Spherics on Abû Nasr's recension, spoke very highly of the latter's merits. A set of his 15 smaller works have been published by the Dâiratu'l-Ma'ârif, Hyderabad (Deccan). They were mostly written by the master in response to his pupil, Al-Bīrūnī's queries. Abû-Nasr had written a complete work on Astronomy entitled as Al-Majistî ash-Shâhi which is most probably altogether lost.

His major work based on Menelaus' Spherics has, however, survived and been published in Berlin in 1936. His death should have taken place much earlier than 427 A.H., as Al-Bīrūnī mentions him as of a dead person in 427 when he wrote his Risâlah on the bibliography of his own and Ar-Râzî's works.

¹⁰ See Al-Tahdîd (Parts only published by Zeki Valido in the Memoir No. 93 of Ind. Arch. Survey) pp. 58-59 etc.

¹¹Yâqût, p. 182 (Cairo Edition).…

¹² Al-Birûnî himself says (p. 187).…

¹³ For a short study on Qabus as a writer of Arabic prose and poetry see Zakî Mubarak's An-Nasru 'l-Funni fî Qarani'r-Rabî, pp. 277-289.

¹⁴ I understand that Edm. O. Von Lippman has attempted to make an inventory of the scientific subjects in Al-Âthâr in Abhandluingen und Vortage, Leipzig, Vol. I. 1906, p. 97.

¹⁵" The test of these most interesting letters has been published in Jâmi'u'l-Badâ'i, … Cairo, 1335 A.H./1917 … and the Persian translation in Deh-Khudâ's Life of Al-Bīrūnī, Tehran, pp. 29-64

¹⁶.. wrongly cited in Ibrahim b-Sinafi's work Harakatu 'sh Shams. p. 56.

¹⁷Kitabu 't-Tahdîd.

¹⁸ Al-Bīrūnī Commemoration Volume, pp. 203-208.

¹⁹ Yâqût quotes Al-Bīrūnī…

²⁰Al-Tahdid, p. 60 (Zekî's extracts) …

²¹ Zakî Validi, pp. 9-53.…

²² I am informed by the Hon'ble Maulânâ Abu'l-Kalâm Azâd that he is taking personal interest in the matter and it is hoped that before long Al-Qârûn may at last be published now.

²³ The entire subject was ably dealt with in a small brochure containing the text, translation, notes and comparative table by Mr. Muhammad Fârooq, M.Sc. (Alig.), published at Aligarh and privately circulated for opinion in 1929.

²⁴ Some of Al-Biruni's own works indicate his presence in Ghaznah in the years 409-411, 416, 418, 422 A.H., and subsequent years. I am, therefore, not inclined to believe that he remained in India for many years continuously. On the other hand it appears that he visited it off and on, mostly carrying on his work with the help of the Pundits in Ghaznah.

²⁵A1-Jamâhir, p. 88. …

²⁷ p 115 Zeki Validi'swork.

²⁸ Op. Cit., pp. 226-227., an interesting autobiographical anecdote. While at Rai (Persia), Al-Biruni was entertained by a businessman who possessed complete sets of chinaware which were valued very highly in those times, a single good piece costing 10 guineas (dinars).

²⁹ p. 198 Jâmi'-i Bahâdur Khâni (1935).

³⁰ 2 Volumes; Cairo, 1943.

³¹ On Ibn-i Sînâ's views on Optics, see Kitâbu 'sh-Shifâ, Volume 1, pp. 307-332 (Arabic Text of Tehran) and pp. 76-107 (Persian translation of Kilábu 'n-Nafs from Ash-Shifâ called "Ravân Shinâsî" by Aqa-i Saìrafi).

³² Zeki's work, pp. 54-58.

For Al-Biruni's similar geological views on India, suggesting that Northern Indian Plains were once seas and filled up in the course of time by the natural causes, see his Indica, Sachau's translation, Volume 1, p. 98.

³³ pp. 203-208.

³⁴ For all these and other works of Al-Biruni please see my "Al-Biruni" (2nd Edition, 1927) pp. 109-138.

³⁵Ifrâdu'l-Miqâl, pp. 36-37.

³⁶ Op. Cit. p. 8.

³⁷ Al-Biruni's liking for both is everywhere evident, and numerous instances can be cited, e.g. his not being satisfied with the previous measurements of the Earth and of the Obliquity of the Ecliptic.

³⁸ In proof of his religious-mindedness we may cite his attempts to deal with the problem regarding the direction of the Ka'aba, and his full discussion in ïfrâ-Miqâl pp. 160-197 for fixing prayer times according to the various Schools of Muslim Jurisprudence and the description of the methods and instruments to be devised for that purpose.

³⁹A1-Jamâhir, p. 215.

⁴⁰ Al-Biruni's hostile attitude to Ar-Râzi's views on Religion and Alchemy may be ascertained by referring to the interesting Risâlah of 427 A.H. re. to bibliographies of Ar-Râzi's as well as Al-Biruni's own works.

⁴¹Kitâbu't-Tafhîm, p. 316.…

⁴²Ar-Risâlah, pp. 41-42.

⁴³ Quoted by Deh-Khudâ, p. 12.

⁴⁴ See Nallino's Article on Muslim Astrology etc. in the Encyclopaedia of Religion, Vol. 12, pp. 88-101.

⁴⁵ [cf.] Islamic Culture (Hyderabad Deccan), Vol. VI, p. 531.…

⁴⁶ Yâqût's Irshâd, p. 188 (Cairo Edition).