SCIENCES


The Arabs who had wielded the arms with such remarkable success, that they had become the masters of a third of the known world in a short span of thirty years, met with even greater success in the realm of knowledge. But the west has persistently endeavored to under-rate the achievements of Islam. Writing in his outspoken book the intellectual Development of Europe, John William Draper says, "I have to deplore the systematic manner in which the literature of Europe has contrived to put out of sight our scientific obligations to the Muhammadans. Surely they can not be much longer hidden. Injustice founded on religious rancor and national conceit cannot be perpetuated for ever. What should the modern astronomer say, when, remembering the contemporary barbarism of Europe, he finds the Arab Abul Hassan speaking of turbes, to the extremities of which ocular and object diopters, perhaps sights, were attached, as used at Meragha? What when he reads of the attempts of Abdur Rahman Sufi at improving the photometry of stars? Are the astronomical tables of Ibn Junis (A.D. 1008) called the Hakemite tables, or the Ilkanic tables of Nasir-ud-din Toosi, constructed at the great observatory just mentioned, Meragha near Tauris (1259 A.D.), or the measurement of time by pendulum oscillations, and the method of correcting astronomical tables by systematic observations are such things worthless indications of the mental State? The Arab has left his intellectual impress on Europe, as, before long, Christendom will have to confess; he has indelibly written it on the heavens, as any one may see who reads the names of the stars on a common celestial globe."


What is Science?

Science, has been defined as, "the ordered knowledge of natural phenomena and the relations between them. Its end is the rational interpretation of the facts of existence as disclosed to us by our faculties and senses." The celebrated scientist Sir J. Arthur Thomson considers science to be "the well criticized body of empirical knowledge declaring in the simplest and tersest terms available at the time what can be observed and experimented with, and summing up uniformities of change in formulae which are called laws verifiable by all who can use the methods." According to another well known scientist Karl Pearson the hypotheses of science are based on "observed facts, which, when confirmed by criticism and experiment, are turned into laws of Nature."


Experimental Method

Observation and experiment are the two sources of scientific knowledge. Aristotle was the father of the Greek sciences, and has made a lasting contribution to physics, astronomy, biology, meteorology and other sciences. The Greek method of acquiring scientific knowledge was mainly speculative, hence science as such could make little headway during the time of the Greeks.

The Arabs who were more realistic and practical in their approach adopted the experimental method to harness scientific knowledge. Observation and experiment formed the vehicle of their scientific pursuits, hence they gave a new outlook to science of which the world had been totally unaware. Their achievements in the field of experimental science added a golden chapter to the annals of scientific knowledge and opened a new vista for the growth of modern sciences. Al-Ghazali was the follower of Aristotle in logic, but among Muslims, Ishraqi and Ibn Taimiyya were first to undertake the systematic refutation of Greek logic. Abu Bakr Razi criticized Aristotle's first figure and followed the inductive spirit which was reformulated by John Stuart Mill. Ibn Hazm in his well known work Scope of Logic lays stress on sense perception as a source of knowledge and Ibn Taimiyya in his Refuttion of Logic proves beyond doubt that induction is the only sure form of argument, which ultimately gave birth to the method of observation and experiment. It is absolutely wrong to assume that experimental method was formulated in Europe. Roger Bacon, who, in the west is known as the originator of experimental method in Europe, had himself received his training from the pupils of Spanish Moors, and had learnt everything from Muslim sources. The influence of Ibn Haitham on Roger Bacon is clearly visible in his works. Europe was very slow to recognize the Islamic origin of her much advertised scientific (experimental) method. Writing in the Making of Humanity Briffault admits, "It was under their successors at the Oxford School that Roger Bacon learned Arabic and Arabic science. Neither Roger Bacon nor his later namesake has any title to be credited with having introduced the experimental method. Roger Bacon was no more than one of the apostles of Muslim science and method to Christian Europe; and he never wearied of declaring that the knowledge of Arabic and Arabic science was for his contemporaries the only way to true knowledge. Discussions as to who was the originator of the experimental method......are part of the colossal misrepresentation of the origins of European civilization. The experimental method of Arabs was by Bacon's time widespread and eagerly cultivated throughout Europe....Science is the most momentous contribution of Arab civilization to the modern world, but its fruits were slow in ripening. Not until long after Moorish culture had sunk back into darkness did the giant to which it had given birth, rise in his might. It was not science only which brought Europe back to life. Other and manifold influences from the civilization of Islam communicated its first glow to European life. For although there is not a single aspect of European growth in which the decisive influence of Islamic culture is not traceable, nowhere is it so clear and momentous as in the genesis of that power which constitutes the permanent distinctive force of the modern world, and the supreme source of its victory-natural science and the scientific spirit.., The debt of our science to that of the Arabs does not consist in startling discoveries or revolutionary theories; science owes a great deal more to Arab culture, it owes its existence....The ancient world was, as we saw, pre-scientific. The astronomy and mathematics of Greeks were a foreign importation never thoroughly acclimatized in Greek culture. The Greeks systematized, generalized and theorized, but the patient ways of investigations, the accumulation of positive knowledge, the minute methods of science, detailed and prolonged observation and experimental enquiry were altogether alien to the Greek temperament. Only in Hellenistic Alexandria was any approach to scientific work conducted in the ancient classical world. That spirit and those methods were introduced into the European world by the Arabs."' In his outstanding work The Reconstruction of Religious Thought in Islam, Dr. M. Iqbal, the poet of Islam writes, "The first important point to note about the spirit of Muslim culture then is that for purposes of knowledge, it fixes its gaze on the concrete, the finite. It is further clear that the birth of the method of observation and experiment in Islam was due not to a compromise with Greek thought but to prolonged intellectual warfare with it. In fact the influence of Greeks who, as Briffault says, were interested chiefly in theory, not in fact, tended rather to obscure the Muslim's vision of the Quran, and for at least two centuries kept the practical Arab temperament from asserting itself and coming to its own." Thus the experimental method introduced by the Arabs was responsible for the rapid advancement of science during the mediaeval times.


Chemistry

Chemistry as a science is unquestionably the invention of the Muslims. It is one of the sciences in which Muslims have made the greatest contribution and developed it to such a high degree of perfection that they were considered authorities in this science until the end of the 17th century A. D. Jabir and Zakariya Razi have the distinction of being the greatest chemists the mediaeval times produced. Writing in his illuminating History of the -Arabs, Philip K. Hitti acknowledges the greatness of Arabs in this branch of science when he says, "After materia medica, astronomy and mathematics, the Arabs made their greatest scientific contribution in chemistry. In the study of chemistry and other physical sciences, the Arabs introduced the objective experiment, a decided improvement over the hazy speculation of Greeks. Accurate in the observation of phenomena and diligent in the accumulation of facts, the Arabs nevertheless found it difficult to project proper hypotheses."

Jabir Ibn Hayyan (Geber) who flourished in Kufa about 776 A.D. is known as the father of modern chemistry and along with Zakariya Razi, stands as the greatest name in the annals of chemical science during mediaeval times. He got his education from Omayyad Prince Khalid Ibn Yazid Ibn Muawiyah and the celebrated Imam Jafar al-Sadiq. He worked on the assumption that metals like lead, tin and iron could be transformed into gold by mixing certain chemical substances. It is said that he manufactured a large quantity of gold with the help of that mysterious substance and two centuries later, when a street was rebuilt in Kufa a large piece of gold was unearthed from his laboratory. He laid great emphasis on the importance of experimentation in his research and hence he made great headway in chemical science, Western writers credit him with the discovery of several chemical compounds, which are not mentioned in his twenty-two extant Arabic works. According to Max Meyerhof "His influence may be traced throughout the whole historic course of European alchemy and chemistry." He is credited, with the writing of 100 chemical works. "Nevertheless, the works to which his name was attached" says Hitti, "were after the 14th century, the most influential chemical treatises in both Europe and Asia."" He explained scientifically the two principal operations of chemistry, calcination and reduction, and registered a marked improvement in the methods of evaporation, sublimation filtration, distillation and crystallization. Jabir modified and corrected the Aristotelian theory of the constituents of metal, which remained unchanged until the beginning of modern chemistry in the 18th century. He has explained in his works the preparation of many chemical substances including "Cinnabar" (sulphide of mercury) and arsenic oxide. It has been established through historical research that he knew how to obtain nearly pure vitrilos, alums, alkalis and how to produce 'the so-called liver' and milk of sulphur by heating sulphur with alkali. He prepared mercury oxide and was fully conversant with the preparation of crude sulphuric and nitric acids. He knew the method of the solution of gold and silver with this acid. His chemical treatises on such subjects have been translated into several European languages including Latin and several technical scientific terms invented by Jabir have been adopted in modern chemistry. A real estimate of his achievements is only possible when his enormous chemical work including the Book of Seventy were published. Richard Russell (1678, A.D.) an English translator ascribes a book entitled Sun of Perfection to Jabir. A number of his chemical works have been published by Berthelot. His books translated into English are the Book of Kingdom, Book of Balances and Book of Eastern mercury. Jabir also advanced a theory on the geologic formation of metals and dealt with many useful practical applications of chemistry such as refinement of metals, preparation of steel and dyeing of cloth and leather, varnishing of waterproof cloth and use of manganese dioxide to color glass.

Jabir was recognized as the master by the later chemists including al-Tughrai and Abu al-Qasim al-Iraqi who flourished in the 12th and 13th centuries respectively. These Muslim chemists made little improvement on the methods of Jabir. They confined themselves to the quest of the legendary elixir which they could never find.

Zakariya Razi known as Rhazas in Latin is the second great name in mediaeval chemical science. Born in 850 A.D. at Rayy, he is known as one of the greatest physicians of all times. He wrote Kitab al Asrar in chemistry dealing with the preparation of chemical substances and their application. His great work of the art of alchemy was recently found in the library of an Indian prince. Razi has proved himself to be a greater expert than all his predecessors, including Jabir, in the exact classification of substances. His description of chemical experiments as well as their apparatus are distinguished for their clarity which were not visible in the writings of his predecessors. Jabir and other Arabian chemists divided mineral substances into bodies (gold, silver etc.), souls (sulphur, arsenic, etc.) and spirits (mercury and sal-ammoniac) while Razi classified his mineral substances as vegetable, animal and mineral.

The mineral substances were also classified by Al-Jabiz. Abu Mansur Muwaffaq has contributed to the method of the preparation and properties of mineral substances. Abul Qasim who was a renowned chemist prepared drugs by sublimation and distillation. High class sugar and glass were manufactured in Islamic countries. The Arabs were also expert in the manufacture of ink, lacquers, solders, cements and imitation pearls.


Physics

The Holy Quran had awakened a spirit of enquiry among the Arabs which was instrumental in their splendid achievements in the field of science, and according to a western critic led them to realize that "science could not be advanced by mere speculation; its only sure progress lay in the practical interrogation of nature. The essential characteristics of their method are experiment and observation. In their writings on Mechanics, hydrostatics, optics, etc., the solution of the problem is always obtained by performing an experiment, or by an instrumental observation. It was this that made them the originator of chemistry, that led them to the invention of all kinds of apparatus for distillation, sublimation, fusion and filteration; that in astronomy caused them to appeal to divided instrument, as quadrant and astrolabe; in chemistry to employ the balance the theory of which they were perfectly familiar with; to construct tables of specific gravities and astronomical tables, that produced their great improvements in geometry and trigonometry."

The Muslims developed physics to a high degree and produced such eminent physicist as Kindi, Jahiz, Banu Musa, Beruni, Razi and Abdur Rahman Ibn Nasr.

Abu Yusuf Ibn Ishaq, known as al-Kindi was born at Kufa in the middle of the 9th century and flourished in Baghdad. He is the most dominating and one of the greatest Muslim scholars of physics. Over and above this, he was an astrologer, philosopher, alchemist, optician and musical theorist. He wrote more than 265 books, the majority of which have been lost. Most of his works which survived are in Latin having been translated by Gerard of Cremona. Of these fifteen are on meteorology, several on specific weight, on tides, on optics and on reflection of light, and eight are on music. His optics influenced Roger Bacon. He wrote several books on iron and steel to be used for weapons. He applied mathematics not only to physics, but also to medicine. He was therefore regarded by Cardon, a philosopher of the Renaissance, "as one of the 12 subtlest minds." •He thought that gold and silver could only be obtained from mines and not through any other process. He endeavored to ascertain the laws that govern the fall of bodies. Razi investigated on the determination of specific gravity of means of hydrostatic balance, called by him Mizan-al-Tabii. Most of his works on physics, mathematics, astronomy and optics have perished. In physics his writings deal with matter, space, time and motion. In his opinion matter in the primitive state before the creation of the world was composed of scattered atoms, which possessed extent. Mixed in various proportions with the articles of void, these atoms produced these elements which are five ih number namely earth, air, water, fire and celestial element. Fire is created by striking iron on the stone.

Abu Rehan Beruni, was a versatile genius, who adorned the durbar of Mahmud of Ghazni. His outstanding achievement in the realm of physics was the accurate determination of the weight of 18 stones. He also discovered that light travels faster than sound. He has also contributed immensely to geological knowledge by providing the correct explanation of the formation of natural spring and artesian wells, He suggested that the Indus valley was formerly an ancient basin filled with alluvial soil. His Kitab al Jawahir deals with different types of gems and their specific gravity. A voluminous unedited lapidary by Betuni is kept in manuscript form in the Escorial Library. It deals with a large number of stones and metals from the natural, commercial and medical point of view. Barlu Musa has left behind him a work on balance, while Al-Jahiz used hydrostatic balance to determine specific gravity. An excellent treatise had been written by Al-Naziri regarding atmosphere.

Khazini, was a well known scientist of Islam, who explained the greater density of water when nearer to the centre of the earth. Roger Bacon, who proved the same hypotheses afterwards based his proof on the theories advanced by Khazini. His brilliant work Mizanul Hikma deals with gravity and contains tables of densities of many solids and liquids. It also contains "observation on capillarity, uses of aerometer to measure densities and appreciate the temperature of liquids, theory of the lever and the application of balance to building." Chapters on weights and measures were written by Ibn Jami and Al-Attar. Abdur Rahman Ibn Nasr wrote an excellent treatise on weights and measures for the use of Egyptian markets.


Biology

The Muslim scientists made considerable progress in biology especially in botany, and developed horticulture to a high degree of perfection. They paid greater attention to botany in comparison to zoology. Botany reached its zenith in Spain. In zoology the study of the horse was developed almost to the tank of a science. Abu Ubaidah (728--825 A. D.) who wrote more than 100 books, devoted more than fifty books to the study of the horse.

Al-Jahiz, who flourished in Basra is reputed to be one of the greatest zoologists the Muslim world has produced. His influence in the subject may be traced to 'the Persian'Al-Qazwini' and the Egyptian 'Al-Damiri'. His book 'Ritab al Haywan' (book ori animals) contains germs of later theories of evolution, adaptation and animal psychology. He was the first to note changes in bird life through migrations, Re described the method of obtaining 'ammonia from animal offal by dry distilling.'

Al-Damiri, who died in 1405 in Cairo and who was influenced by Al-Jahiz is the greatest Arab zoologist. His book Hayat Haywan (Life of animal) is the most important Muslim work in zoology. It is an encyclopedia on animal life containing a mine of information on the subject. It contains the history of animals and preceded Buffon by 700 years.

Al-Masudi, has given the rudiments of the theory of evolution in his well known work Meadows of gold. Another of his works Kitab al-Tanbih wal Ishraq advances his views on evolution namely from mineral to plant, from plant to animal and from animal to man.

In botany Spanish Muslims made the greatest contribution, and some of them are known as the greatest botanists of mediaeval times. They were keen observers and discovered sexual difference between such plants as palms and hemps. They roamed about on sea shores, on mountains and in distant lands in quest of rare botanical herbs. They classified plants into those that grow from seeds, those that grow from cuttings and those that grow of their own accord, i.e., wild growth. The Spanish Muslims advanced in botany far beyond the state in which "it had been left by Dioscorides and augmented the herbology of the Greeks by the addition of 2,000 plants" Regular botanical gardens existed in Cordova, Baghdad, Cairo and Fez for teaching and experimental purposes. Some of these were the finest in the world.

The Cordovan physician, Al-Ghafiqi (D. 1165) was a renowned botanist, who collected plants in Spain and Africa, and described them most accurately. According to G. Sarton he was "the greatest expert of his time on simples. His description of plants was the most precise ever made in Islam; he gave the names of each in Arabic, Latin and Berber".l His outstanding work Al Adwiyah al Mufradah dealing with simples was later appropriated by Ibn Baytar."

Abu Zakariya Yahya Ibn Muhammad Ibn AlAwwan, who flourished at the end of 12 century in Seville (Spain) was the author of the most important Islamic treatise on agriculture during the mediaeval times entitled Kitab al Filahah. The book treats more than 585 plants and deals with the cultivation of more than 50 fruit trees. It also discusses numerous diseases of plants and suggests their remedies. The book presents new observations on properties of soil and different types of manures.

Abdullah Ibn Ahmad Ibn al-Baytar, was the greatest botanist and pharmacist of Spain--in fact the greatest of mediaeval times. He roamed about in search of plants and collected herbs on the Mediterranean littoral, from Spain to Syria, described more than 1,400 medical drugs and compared them with the records of more than 150 ancient and Arabian authors. The collection of simple drugs composed by him is the ilaost outstanding botanical work in Arabic. "This book, in fact is the most important for the whole period extending from Dioscorides down to the 16th century." It is an encyclopedic work on the subject. He later entered into the service of the Ayyubid king, al-Malik al-kamil, as his chief herbalist in Cairo. From there he travelled through Syria and Asia Minor, and died in Damascus. One of his works Al-Mughani-fi al Adwiyah al Mufradah deals with medicine. The other Al Jami Li al Adwiyah al Mufradah is a very valuable book containing simple remedies regarding animals, vegetable and mineral matters which has been described above. It deals also with 200 novel plants which were not known up to that time. Abul Abbas Al-Nabati also wandered along the African Coast from Spain to Arabia in search of herbs and plants. He discovered some rare plants on the shore of Red Sea.

Another botanist Ibn Sauri, was accompanied by an artist during his travels in Syria, who made sketches of the plants which they found.

Ibn Wahshiya, wrote his celebrated work al-Filahah al-Nabatiyah containing valuable information about: animals and plants.

Many Cosmographical encyclopedias have been written by Arabs and Persians, which contain sections on animals, plants and stones, of which the best known is that of Zakariya al-Kaiwini, who died in 1283 A. D. Al-Dinawari wrote an excellent 'book of plants' and al-Bakri has written a book describing in detail the 'Plants of Andalusia'

Ibn Maskwaih, a contemporary of Al-Beruni, advanced a definite theory about evolution. According to him plant life at its lowest stage of evolution does not need any seed for its birth and growth. Nor does it perpetuate its species by means of the seed.

The great advancement of botanical science in Spain led to the development of agriculture and horticulture on a grand scale. "Horticulture improvements" says G. Sarton, "constituted the finest legacies of Islam, and the gardens of Spain proclaim to this clay one of the noblest virtues of her Muslim conquerors- The development of agriculture was one of the glories of Muslim Spain."'


Transmission to the West

The Muslims were the pioneers of sciences and arts during mediaeval times and formed the necessary link between the ancients and the moderns. Their light of learning dispelled the gloom that had enveloped Europe. Moorish Spain was the main source from which the scientific knowledge of the Muslims and their great achievements were transmitted to France, Germany and England. The Spanish universities of Cordova, SeviIle and Granada were thronged with Christian and Jewish students who learnt science from the Muslim scientists and who then popularized them in their native lands. Another source for the transmission of Muslim scientific knowledge was Sicily, where during the reign of Muslim kings and even afterwards a large number of scientific works were translated from Arabic into Latin. The most prominent translators who translated Muslims works from Arabic into European languages were Gerard of Cremona, Adelard of Bath, Roger Bacon and Robert Chester. Writing in his celebrated work Moors in Spain Stanley Lane Poole says, "For nearly eight centuries under the Muhammadan rulers, Spain set out to all Europe a shining example of a civilized and enlightened State--Arts, literature and science prospered as they prospered nowhere in Europe. Students flocked from France, Germany and England to drink from the fountain of learning which flowed down in the cities of Moors. The surgeons and doctors of Andalusia were in the van of science; women were encouraged to serious study and the lady doctor was not always unknown among the people of Cordova. Mathematics, astronomy and botany, history, philosophy and jurisprudence, were to be mastered in Spain, and Spain alone. The practical work of the field, the scientific methods of irrigation, the arts of fortification and shipbuilding, of the highest and most elaborate products of the loom, the gravel and the hammer, the potter's wheel and mason's trowel, were brought to perfection by the Spanish Moors. Whatever makes a kingdom great and prosperous, whatever tends to refinement and civilization was found in Muslim Spain."

The students flocked to Spanish cities from all parts of Europe to be infused with the light of learning which lit up Moorish Spain. Another western historian writes, "The light of these universities shone far beyond the Muslim world, and drew students to them from east and west. At Cordova in particular there were a number of Christian students, and the influence of Arab philosophy coming by way of Spain upon universities of Paris, Oxford and North Italy and upon western Europe thought generally, was very considerable indeed. The book copying industry flourished at Alexandria, Damascus, Cairo and Baghdad and about the year 970, there were 27 free schools open in Cordova for the education of the poor.

Such were the great achievements of Muslims in the field of science which paved the way for the growth of modern sciences.


SCIENTIFIC INVENTIONS

Muslims distinguished themselves not only as theoretical scientists and scientific thinkers, but contributed through innumerable inventions to the growth of the modern sciences. Though the mediaeval Muslims had very meager resources at their command as compared to those of the present age, they achieved a great deal. They replaced the old speculative method of the Greeks with an experimental method, which in later periods formed the basis of all scientific investigations.


Inventions

Abul Hasan is distinguished as the inventor of the Telescope, which he described to be a “Tube, to the extremities of which were attached diopters".

The Pendulum was invented by Ibn Yunus, a genius in science who lived in the reign of Aziz Billah and Hakim bi-Amr-illah, the Fatimid monarchs of Egypt. The invention of the Pendulum led to the measurement of time by its oscillations. His outstanding work Sijul Akbar al-Hakimi, named after his celebrated patron Hakim bi-Amr-illah, was acknowledged to be the masterpiece on the subject replacing the work of Ptolemy. It was translated into Persian by Omar Khayyam in 1079.

The first watch was made by Kutbi, a renowned watch-maker of his time. During the Abbasid reign the use of a watch became quite common and the famous Harun-ar-Rashid once dispatched a watch as a gift to his celebrated contemporary, the French Emperor Charlemagne. At that time a watch was considered a novel thing in Europe and was regarded as an object of wonder. Mustansariya, the well-known university of Baghdad had a unique clock with a dial blue like the sky and a sun which continually moved over its surface denoting the time. Maulana Shibli, the famous Urdu litterateur, has described a watch of Damascus in the following words: "The watch was kept in the door of a wall. It contained copper plates and twelve doors. There was an Eagle (Bat) standing in the Ist and the last plate. At the end of each hour, these two eagles lay down on the copper plates and hence a sound was produced to show the time. At twelve all the doors were closed. This system was being repeated continuously". The construction of water clocks was also common in Islamic Countries. "The Arabs were skilful in the construction of clepsydras and water clocks with automata," says a European writer.

The invention of Mariners Compass, which revolutionized sea borne commerce and oceanic shipping and enabled the Arabs to roam over the stormy seas in quest of new lands and additional markets for their commodities, is essentially a contribution of the Muslims to the world of science. Knowledge about the properties of the needle, can no doubt be traced to Chinese sources, but putting it into working shape, in the form of a mariners' compass, was the achievement of Muslim scientists. The compass was probably invented for the purpose of finding out the Qibla for Prayers.

Mir Fatehullah Khan is known to history as the inventor of gun and gunpowder. The presumption that gunpowder was first made by the Chinese does not stand the test of historical research. Writing in his book Arab Civilization, the author says that "gunpowder was a great invention of the Arabs who were already using guns". Guns were used by Arabs in 1340 A.D. in the defense of Al-Bahsur, when Franzdol besieged it. The statement of Dr. Leabon about the invention of gunpowder by the Arabs is further corroborated by Mr. Scott in his well-known work, History of the Moorish Empire in Spain.

It has been acknowledged by Joseph Hell in his book, Arab Civilization, that the distinction of inventing photography goes to Ibn al-Hashem, who is not only credited with its invention but also its development. Muhammad Musa, a great scholar of geography, has the unique distinction of being the inventor of an instrument by which the earth could be measured. He also invented the "Astrolabe". These novel instruments invented by him have been preserved in the Museum of Madrid (Spain).

A unique instrument was invented by Abu Solet Umayya in 1134 A.D. through which a sunken ship would be raised--which greatly helped in the salvage expeditions of mediaeval times.

The credit for manufacturing soap goes to Arab chemists, who introduced it to the world. The first paper in Islamic countries was manufactured in 794 A.D. in Baghdad by Yusuf Bin Omar. The paper manufactured in Arab countries was of superior quality than that made in Europe. In the manufacture of cloth, Muslims particularly in Spain exhibited marvelous skill and taste. Their woven cloth captured almost all the big markets of the world and was considered to be the finest as well as extremely durable.

Al-Masudi who died in Cairo in 957 A.D. may be called the "Pliny of the Arabs" In his celebrated work The Meadows of Gold, he has described an earthquake, and the first windmill which was also invented by a Muslim.

Giralda or "The Tower of Seville", was the first observatory in Europe. It was built in 1190 A.D., in the Spanish town of Seville under the supervision of the celebrated Mathematician, Jabir Ibn Afiah. It was meant for the observation of heavenly bodies. It was later turned into a belfry by Christian conquerors, who, after the expulsion of the Moors, did not know how to use it.

Bold experiments and unique innovations in the field of mathematics were carried out by Muslim mathematicians who developed this science to an exceptionally high degree. Algebra may be said to have been invented by the Greeks, but according to Oelsner, "it was confined to furnishing amusement for the plays of the goblet" Muslims developed it and applied it to higher purposes. They invented spherical trigonometry, discovered the tangent and were first, "to introduce the sine of arc in Trigonometrical Calculations" Zero is an invaluable addition made to mathematical science by the Muslims. They have also shown remarkable progress in mathematical geography.

The Muslims have made a lasting contribution to the development of Medical Science. Razi (Rhazes), Ibn Sina (Avicenna), and Abu Ali al-Hasan (Alhazen) were the greatest medical scholars of mediaeval times. Al-Razi was the inventor of "Seton" in Surgery and the author of Al-Judari wal Hasbak, an authentic book dealing with measles and small pox. Avicenna wrote Al-Qanun Jil Tib known as Cannon, which was the most widely studied medical work of medieval times and was reprinted more than twenty times during the last 30 years of the 15th century in many different languages. Alhazen was the world's greatest authority on "optics". The contagious character of the plague and its remedies were discovered by Ibn Katina, a Moorish Physician.

Ibn Firnas is credited with making glass from stones. He had constructed his home as a sort df planetarium where one could see stars, clouds and even lightning. According to Hitti 'Ibn Firnas was the first man in Arab history to make a scientific attempt at flight. His flying equipment consisted of a suit of feathers with wings, which, we are told carried him a long distance, in the air. When he alighted, however, he hurt himself because his suit was not provided with a tail.


ASTRONOMY

Baghdad, the fairy city of the Arabian Nights and capital of the famous Harun-ar-Rashid, the greatest emperor of his time, had the distinction of being the foremost centre of art and culture during mediaeval times. Renowned scholars and translators, artists and scientists flocked to this great metropolis from all parts of the world and adorned the learned assemblies of Harun and Mamun, who, besides being celebrated scholars themselves, were the greatest patrons of learning that the world has ever known. The Darul Hukama (House of Wisdom) founded by Mamun-ar-Rashid in Baghdad housed some of the most eminent scholars of the world belonging to different castes and creeds. The spade work done by the scholars of the House of Wisdom provided the foundation by which the stately edifice of Islamic learning was built. The caliphate of Mamun, undoubtedly constitutes the most glorious epoch in saracenic history and has rightly been called the 'Augustan age of Islam'. "The twenty years of his reign" says Ameer Ali," have left enduring monuments of the intellectual development of the Muslim in all directions of thought. Their achievements were not restricted to any particular branch of science or literature, but ranged over the whole course of the domain of intellect; speculative philosophy and 'belles lettres' were cultivated with as much avidity as the exact sciences".' "We see for the first time" says Oelsner, "perhaps in the history of the world, a religious and despotic government allied to philosophy, preparing and partaking in its triumphs".

Astronomy, in the real sense, started among the Arabs during the early period of the Abbasid Caliphate. It was much influenced by Sidhanta, a work in Sanskrit brought from India to Baghdad and translated into Arabic by Ibn Ibrahim al-Fazari and later on by Abu Musa Khwarizmi. Pahlavi tables (zij) compiled during the Sasanid period and Greek astronomical works translated during this period prepared the ground for Arabian astronomy. Ptolemy's Al-magest went into several translations in Arabic--the best being the one by Hajjaj Ibn Mater (827-28) and another by Humayun Ibn Ishaq, revised by Thabit bin Qurra (d/901).

Khwarizmi has written a valuable treatise on astronomy and has compiled his own Tables (zij) which, after two centuries was revised by Spanish atronomer Majriti (011007) and was translated into Latin by Adelard of Bath. This formed the basis of later astronomical pursuits both in the East and the West and replaced all earlier tables of Greek and Indian astronomers. This table was also adopted in China.

Mashallah and Ahmad bin Muhammad alNahavandi were the earliest Arab astronomers who flourished during the reign of Mansur, the second Abbasid Caliph. Mashallah was called the Phoenix of his age by Abul Faraj. He is distinguished for writing several valuable treatises on 'Astrolabe' the armillary sphere and the movements of heavenly bodies which have been acclaimed by later scientists. Ahmad compiled from his observations an astronomical table known as Al-Mustamal which registered an advance over earlier notions of the Greeks and Hindus.

It was during the reign of Mamun, that practical steps were taken for the advancement of astronomy and several observatories equipped with the latest instruments were set up at various places in his domain. One of them was the observatory in Jundeshapur, in south-west Persia. Early in the 9th century A.D. the first regular observations (Rasd) with the best available and fairly accurate instruments were made in this observatory. Mamun got a degree of meridian measured in the plain of Sanjar and followed a method which was much superior to that of Greeks. The astronomical observations made during the reign of Mamun regarding the equinoxes, the eclipses, the apparitions of the comets and' other celestial phenomena, have earned an important place in the astronomical annals of mediaeval times. "The size of the earth was calculated", says Ameer Ali "from the measurement of a degree on the shores of the Red Sea--this at a time when Christian Europe was asserting the flatness of the earth".' Attached to his Darul Hukama (House of Wisdom), Mamun erected at Baghdad near the Shamsiyah gate, an astronomical observatory under the directorship of Sind Ibn All, a converted Jew and Yahya Ibn Abi Mansur (830 or 831 A.D.). According to C. A. - Nallino, "Here astronomers made systematic observation of celestial movements and verified with remarkably precise results all the fundamental elements of the Almagest: the obliquity of the ecliptic, the precession of the equinoxes, the length of the solar year, etc." With the aid of these observations the astronomical tables called the Tested Tables or Tables of Mamun were prepared. According to Ibn al-Ibri, Mamun later established another observatory on Mt. Qasiyum outside Damascus. Afterwards several other observatories were erected at Wasit, Apamea, etc. Musa bin Shakir was a well-known engineer during the reign of Harun-ar-Rashid. His sons, specialized in astronomical researches and earned a great reputation as astronomers during the reign of Mamun and his two successors. Their research regarding the movements of solar and other astral bodies, was remarkable. They ascertained the size of the earth, the obliquity of the ecliptic, the variations of the lunar latitudes and the precession of the equinoxes! The work of the sons of Musa bin Shakir was continued by Al-Naziri and Muhammad bin Isa Abu Abdulla, who made notable additions to it. The invention of the telescope by Abul Hasan forms a landmark in the advancement of astronomical observations and, in improved form, was used with remarkable success in the observatories of Maragha, Cairo and Seville. A number of Mamun's astronomers headed by Musa Khwarizmi and Musa Ibn Shakir successfully engaged in one of the most oblicate geodetic operations, i.e., the determination of the size and the circumference of the earth. The measurement carried out in the plain of Sanjar and also at Palmyra, "yielded 56 2/3 Arabic miles as the length of a degree of the meridian--a remarkably accurate result, exceeding the real length of the degree at the place by about 2,877 feet" says C. A. Nallino.--"This would make the diameter of the earth 6,500 miles and its circumference 20,400 miles".' Muhammad Bin Musa al-Khwarizmi, a versatile genius of Islamic history translated the Sidhanta or Indian tables and wrote a commentary on it. He has written a valuable treatise on astronomy and has compiled his own tables (zij) which after two centuries were revised by the Spanish astronomer Majriti and translated into Latin by Adelard of Bath in 1126 A.D. These formed the basis of later astronomical works in the East and the West, replacing all earlier tables by Greek and Indian astronomers. These tables were also used in China.

Ibrahim al-Fazari was the first Muslim to construct an astrolabe. He wrote on the use of the armillary sphere and prepared tables in accordance with the Arabic years. One of the earliest Arabic treatises on this instrument was written by Isa-al-Asturlabi who resided in Baghdad at about 830 A.D.

Abul Abbas al-Farghani (Alfraganus), a resident of Farghana in Central Asia, was an astronomer of repute, who in 861 A.D., according to Ibn Abi Usabiyah (Vol. I, page 207), supervised for the Abbasid Caliph Al-Mutawakkil the erection of a Nilometer at Fustat.

His well-known work AI-Mudkhil-ila-ilm-hayat-al-aflak (compendium of astronomy) was translated into Latin in 1135 A. D. by John of Seville and Gerard of Cremona. It was also rendered into Hebrew. "The introduction of Astronomy into Christian Europe", says J. W. Draper, "has been attributed to the translation of the works of Muhammad Fargani. In Europe, also, the Arabs were the first to build observatories; the Giralda, or Tower of Seville was erected under the superintendence of Geber, the mathematician"

The Buwayhid Sultans were also great patrons of learning and were surrounded by a galaxy of talented scholars invited from the four corners of the Islamic world. The Buwayhid Sultan Sharaf al-Daulah (982--89, A.D.) founded a good observatory in his palace at Baghdad where such celebrated astronomers as Abdur Rahman al-Sufi, Ahmad al-Saghani and Abul Wafa carried on their research. Abdur Rahman al-Sufi wrote al-kawakib al-Sabitah (fixed stars) which is known as a masterpiece of observational astronomy. Alkohi, another astronomer attached to the same dynasty, studied the movements of the planets and his research regarding the summer solstice and the autumnal equinox were of considerable value. Abul Wafa, born in 939 A. D. in Khorasan and established in Iraq was an outstanding mathematician and astronomer, who introduced the use of the secant as well as the tangent into astronomical observations. Another Buwayhid ruler, Rukn al-Daulah, (932--76 A. D.) patronized Abu Jafar al-Khazin, a well-known astronomer of Khorasan, who ascertained 'the obliquity of the ecliptic and solved a problem of Archimedes which leads to a cubic equation'.

By the close of the tenth century A.D., Baghdad was thronged with hundreds of astronomers including Ali Ibn Amajur and Abul Hasan Ali Ibn Amajur who are known for their accurate calculation of the lunar movements.

Abu Abdulla Ibn Muhammad Ibn Jabir-al Battani (Albategnius-877-91 8 A.D.) a Sabian from Harran was one of the most illustrious astronomers of the East who is known as the Ptolemy of the Arabs. His tables translated into Latin formed the basis for astronomical work in Europe for several centuries. He also wrote a voluminous treatise on the subject and his astronomical tables were an advance over those of Khwarizmi and the Indians. He carried on his studies and observations in al-Raqqah. He was an outstanding original writer and a research scholar of repute who made several emendations to Ptolemy and rectified the calculations for the orbits of the moon and certain other planets. According to Philip K. Hitti, "He’s proved the possibility of annular eclipses of the sun and determined with greater accuracy the obliquity of the ecliptic, the length of the tropical year, end of the seasons and the mean orbit of the sun"."

Persia, which, after the downfall of the Abbasid Caliphate formed the nerve centre of Islamic learning, produced some of the greatest intellectuals of mediaeval times. Great advances were made in almost all branches of knowledge. One of the most outstanding intellectuals of Islam was Abu Rehan Beruni (973--1048 A.D.) who graced the literary meetings of Mahmud Ghaznaui. "Few know physics and metaphysics" says J. N. Sircar, the celebrated Indian historian, "amongst those few the greatest in Asia was Al-Beruni, at once a philosopher and a scientist and preeminent in both of these two seemingly incompatible fields".' Al-Beruni was a distinguished and original scholar of astronomy and other sciences. His Al-Qanun al-Masudi written for his patron Sultan Masud of Ghazni in 1030 A.D. is an astronomical encyclopedia. A short catechism of geometry, arithmetic, astronomy and astrology also written in 1030 A.D. and entitled Al-Tahfin li-awail sinaat al-rajum deals chiefly with the calendars and eras of ancient peoples. The rotation of the earth on its axis and the accurate determination of longitudes and latitudes were also elaborately discussed in this book.

Malik Shah Saljuqi and his illustrious grand vazir Nizamul Mulk Toosi were also great patrons of learning during those times. They established an observatory at Rayy or Neshapur in 1074-75 A.D. where under the guidance of Omar Khayyam and Abdur Rahman al-Hazini astronomical observations were made. Their research led to a reformed calendar which preceded the Gregorian calendar by 600 years. According to Sedillot, who is an authority on the subject, "it is more exact". This calendar formulated by Omar Khayyam was named Al-Tarikh Jalali after his patron Jalaluddin Malik Shah Seljuqi, and is based on an accurate determination of the length of the tropical year. The Gregorian calendar leads to an error of one day in 3,330 years whereas Khayyam's apparently leads to an error of one day in about 5,000 years.

The destruction wrought by the Mongol hordes served a death blow to all cultural and intellectual movements in the world of Islam. The cultural treasures amassed during centuries of intellectual pursuits was reduced to ashes. On the downfall of the Abbasid Caliphate there sprang up small Muslim principalities who kept aloft the candle of learning and vied with each other in the patronage of scholars and scientists. A year after the fall of Baghdad, in 1259 A.D., Hulagu Khan started the construction of the Khaniz observatory in Maragah (Turkistan). This was the best observatory of its time, working under the directorship of the celebrated genius and astronomer of that era, Nasiruddin Toosi, and equipped with the best available instruments including an armillary sphere, the mural quadrant and a solstitial armil. The remains of this observatory are still extant and it was here that Toosi compiled his famous astronomical tables known as al zij' al il khani which earned much popularity throughout Asia including China. Nasiruddin Toosi also wrote Tazkirah fi 'ilm al-Hai'a', an outstanding work on astronomy.

Samarqand, the capital of the famous conqueror Tamerlane became in those days a great centre of Islamic education. An astronomical table prepared in 1437 for a prince of the family of Tamerlane and called Table of Ulugh Beg was much appreciated in Europe and according to Carra De Vaux was published in England in the 18th century A.D.

The Arab civilization of Spain rivaled that of the Abbasid's in the East, and during the middle of the IOth century astronomical studies were especially favored by the rulers of Muslim Spain. The outstanding Spanish astronomers were Al-Majriti of Cordova, al-Zarqali (1029--1087 A.D.) of Toledo, Ibn Afiah (d/2140-50 A.D.) of Seville and Nur-ud-din Abu Ishaq al-Bitruji.

In his famous work Kitab al Hayat (book of astronomy), which was later translated into Latin by Gerard of Cremona, Jabir Ibn Afiah, the celebrated astronomer of the twelfth century, sharply criticized Ptolemy. Against the observations of Ptolemy he rightly observed that the lower planets, Mercury and Venus, have no visible parallaxes. His generalizations of the subject were confirmed by later research.

Al-Zarqali (Arzachel 1029-1087 A.D.) was the foremost astronomical observer of Muslim Spain. He was the celebrated instrument maker who constructed an improved type of astrolabe (a saJilza) on which he wrote a treatise. His calculations of the length of the Mediterranean Sea as 42 degrees was approximately accurate in comparison to Ptolemy's estimate of 62" and Al-Khwarizmi's estimate of 52". He also has the distinction of being the first astronomer to prove the motion of the solar apogee with reference to stars. His works along with those of Al-Battani were studied and appreciated in the West and Copernicus quotes him in his well known work De Revolutionibus Orbizrm Coelestium.

Nur-ud-Din Abu Ishaq al-Bitruji (Alpetragius), was foremost among the last astronomers of Spain, whose outstanding work Kitab al-Hai'a was translated into Latin by Michael Scot in 1217 and into Hebrew in 1259 A.D. He is considered the exponent of a new astronomy and his book marks the culmination of the anti-Ptolemaic movement. According to Draper, "increased accuracy was given to the correction of the astronomical observations by Alhazen's great discovery of atmospheric refraction."

The first observatory in Europe was built by Arabs in Seville. The famous astronomical tower of Seville was constructed under the supervision of Jabir Ibn Afiah in 1190 A.D. With the fall of the Muslim power in Spain it was turned into a belfry by the Christian conquerors who did not know what else to do with it.

"Finally it was through Spanish channels" says Philip K. Hitti, "that the Latin West found its oriental inspiration in astronomy and astrology. The leading Muslim astronomical works were translated in Spain into Latin, and the Alfonsine tables compiled under the aegis of Alfonso X in the 13th century were but a development of Arab astronomy". According to R..Briffault, "Arab astronomy did not forestall Copernicus or Newton, though without it there would have been no Copernicus and Newton" 2

The Muslims, have thus made the greatest contributions to astronomical knowledge during mediaeval times.


MATHEMATICS

Muslims have made immense contributions to almost all branches of the sciences and arts, but mathematics was their favorite subject and its development owes a great deal to the genius of Arab and Persian scholars. The advancement in different branches of mathematical science commenced during the Caliphate of Omayyads, and Hajjaj bin Yusuf, who was himself a translator of Euclid as well as a great patron of mathematicians.


Translations

Whatever mathematical knowledge Arabs inherited came from two sources--the Hindus and the Greeks. The scholars of the Darul Hukarna of Mamun did the largest amount of work for the advancement of the sciences and arts by the Arabs. Abu Abdulla Muhammad Ibrahim-al-Fazari in 772-773 A.D. translated Sidhanta from Sanskrit into Arabic, which, according to G. Sarton provided "possibly the vehicle by means of which the Hindu numerals were transmitted from India to Islam". The works of Greek mathematicians which were translated during the Abbasid Caliphate and served as the starting point for Arab mathematicians were those of Euclid, Ptolemy, Antolyscus, Aristarchos and Archimedes. Hajjaj bin Yusuf was the first to translate Euclid's Elements into Arabic while Abdur Rahman and Muhammad Ibn Muhammad Baqi wrote commentaries on the 10th book of Euclid. The latter's contribution was translated into Latin by Gerard of Cremona and edited by H. Suter in 1907. Ibrahim Ibn-uz-Zaya al-Misri who died in 912 A.D. has written commentaries on Ptolemy's Centiloquim and Proportions, which influenced modern thought immensely. Abul Abbas Nairizi wrote commentaries on the works of Ptolemy and Euclid, which also were later translated into Latin by Gerard of Cremona. Abul Wafa, the celebrated mathematician, included a simplified version of Ptolemy's Almagest in his well known works--Tahir al-Majisty and Kitab al-Kamil. The last of the Arab translators and commentators of Greek works was the eminent Arab mathematician Al-Buzjani who died in 998 A.D. He commented upon and simplified the works of Euclid, Ptolemy and Diophantus.

Arabic translations of the well-known mathematical works of those times gave the Arabs the sources to develop the science of mathematics to an admirably high degree and later scientists owe much to the Arab genius. Writing in The Spirit of Islam, Ameer Ali says, "Every branch of higher mathematics bears tracts of their genius. The Greeks are said to have invented algebra, but among them, as Oelsner has justly remarked, it was confined to furnishing amusement 'for the plays of the goblet'. The Muslims applied it to higher purposes, and thus gave it a value hitherto unknown. Under Mamun they had discovered the equations of the second degree, and very soon after they developed the theory of quadratic aquations and the binomial theorem. Not only algebra geometry and arithmetic, but optics and mechanics made remarkable progress in the hands of the Muslims. They invented spherical trigonometry; they were the first to apply algebra to geometry, to introduce the tangent, and to substitute the sine for the arc in trigonometrical calculations. Their progress in mathematical geography was no less remarkable". Even the so-called enlightened west which has at times taken pains to minimize the greatness of Muslim achievements in furthering the cause of human civilization, had to admit, though half heartedly, the outstanding part played by the Arabs. "For with this limited ambition", says Carra De Vaux in Legacy of Islam, "the Arabs have really achieved great things in science; they taught the use of ciphers, although they did not invent them, and thus became the founders of arithmetic of every day life; they made algebra an exact science and developed it considerably and laid the foundations of analytical geometry; they were indisputably the founders of plane and spherical trigonometry which, properly speaking, did not exist among the Greeks"." Thus Muslims were pioneers in the development of mathematical sciences in mediaeval times.


Arithmetic

Arabs were the founders of everyday arithmetic and taught the use of ciphers to the world.

Musa al-Khwarizmi (780--850 A.D.) a native of Khwarizm, who lived in the reign of Mamun-ar-Rashid, was one of the greatest mathematicians of all times. He composed the oldest Islamic works on arithmetic and algebra which were the principal source of knowledge on the subject for a fairly long time. George Sarton pays glowing tribute to this outstanding Muslim mathematician and considers him "one of the greatest scientists of his race and the greatest of his time".' He systematized Greek and Hindu mathematical knowledge and profoundly influenced mathematical thought during mediaeval times. He championed the use of Hindu numerals and has the distinction of being the author of the oldest Arabic work on arithmetic known as Kitab-ul Jama wat Tafriq. The original version of this work has disappeared but its Latin translation Trattati a" Arithmetic edited by Bon Compagni in 1157 at Rome is still in existence.

Al-Nasavi is the author of Abnugna Fil Hissab Al-Kindi short extracts of which were published by F. Woepeke in the journal Asiatique in 1863. His arithmetic explains the division of fractions and the extraction of square and cubic roots in an almost modern manner. He introduced the decimal system in place of sexagesimal system.

Al-Karkhi was primarily responsible for popularising Hindu numerals before the advent of Arabic ones. His book 'Al-kafi fil Hissab was translated into German by Hochhevin and published at Halle in 1878--80.

Abu Zakariya Muhammad Al-Hissar who probably lived in the 12th century A. D. is the author of Kitab-us-sagh ir-Jil-h issab . One of its important sections was translated and published by H. Suter in 1901. AL-Hissar was the first mathematician who started writing fractions in their present form with a horizontal line. A commentary on his treatise on arithmetic, written by Ibn al-Banna, gained much popularity and was published in French by A. Narre in 1864 and reprinted in Rome in 1865.

Nasir-ud-din Toosi, a versatile genius, who was a prolific writer and has written more than hundreds of valuable books to his credit, has the distinction of being one of the greatest scientists and mathematicians of Islam. Born in 1201 A. D. in Toos (Persia) Nasir-uddin has written Al-mutawassat and a short but concise book on arithmetic which is available both in Arabic and Persian.

Arabic numerals including zero were the greatest contributions made by the Arabs to the mathematical science. The outstanding quality of Arabic numerals lies in the fact that they possess an absolute value. Huroful Ghubar was a novel form of numerals adopted in Spain by 950 A. D. The most significant numeral invented by the Arabs was zero which according to Carra De Vaux "was used by the Arabs at least 250 years before it became known in the west". Before the introduction of the zero it was necessary to arrange all figures in columns to differentiate between tens, hundreds, thousands, etc. The earliest use of the zero is given as 873 A. D.


Algebra

Is a word derived from the Arabic source AlJabar and is the product of Arabic genius.

Al-Khwarizmi the celebrated mathematician is also the author of Hisab Al-Jabr Wal Muqabla, an outstanding work on algebra which contains analytical solutions of linear and quadratic equations. Khwarizmi has the distinction of being one of the founders of algebra who developed this branch of science to an exceptionally high degree. He also gives geometric solutions of quadratic equations, e.g., x2+10x=39 an equation which was repeated by later mathematicians. Robert Chester was the first to translate this book into Latin in 1145 A. D. which introduced Algebra into Europe. Later on this book was translated by Gerard of Cremona also. The Algebra written by Al-Khwarizmi is lucid and well-arranged. After dealing with equations of the second degree, the learned mathematician discussed algebraic multiplications and divisions. Writing in The Legacy of Islam Carra De Vaux says, "In the 18th century Leonardo Fibonacci of Pisa, an algebraist of considerable importance says he owed a great deal to the Arabs."' He travelled in Egypt, Syria, Greece and Sicily and learned the Arabic methods there, recognized it to be superior to the method of Pythagoras and composed a liber Abaci in 15 chapters, the rest of which deals with algebraic calculations. Leonardo enumerates the six cases of the quadratic equations just as Al-Khwarizmi gives them. The translation by Robert Chester of Khwarizmi's algebra marks the beginning of the era of the introduction and advancement of this branch of science in Europe. "The importance of Robert's Latin translation of Khwarizmi's algebra", says a modern orientalist, "can hardly be exaggerated because it marked the beginning of European Algebra."

Omar Khayyam, the celebrated poet, philosopher, astronomer and mathematician has left behind an excellent book on algebra. His works on algebra were translated in 1851, while his Ruhaiyat were first published in 1859. The manuscripts of his principal works exist in Paris and in the India Office London; Mosadrat, researches on Euclid's axioms, and Mushkilat-i-Hissab, dealing with complicated arithmetical problems, have been preserved in Munich (Germany). According to V• Minorsky, "He was the greatest mathematician of mediaeval times." His primary contribution is in algebra in which he has registered much advance on the work of the Greeks. His algebra is an advance on that of Khwarizmi too in the degree of equations--as the greater Part of Omar's book is devoted to the cubic equations only. His algebra deals with the geometric and algebraic solution of equation of the second degree and includes an admirable classification of equations based on the number and different terms which they include. He recognizes thirteen different forms of cubic equations. His solution of cubic and quadratic equations by the conic section method is probably the most advanced work of Arabic mathematics that has survived. "His skill as a geometer" says Carra De Vaux, "is equal to his literary erudition and reveals real logical power and penetration."

Abul Kamil improved upon the algebra of Khwarizmi. He dealt with quadratic equations, multiplication and division of algebraic quantities, addition and subtraction of radicals and the algebraic treatment of' pentagons and decagons.

Abu Bakr Karkhi, who adorned the court' of Fakhrul Mulk in the beginning of 11th century wrote an outstanding treatise on algebra known as AlFakhri. This is one of the best books on the subject left by a Muslim mathematician and was published by Woepeke in Paris in 1853 A.D.

Geometry, like other branches of mathematics, geometry made much headway in the hands of Muslims. The three famous brothers Muhammad, Ahmad and Hassan, sons of Musa bin Shakir, wrote an excellent work on geometry which was translated into Latin by Gerard of Cremona. This was later translated into German by M. Kurtaza.

Abul Wafa Al-Buzjani, (940--997, 998 A. D.) is the author of Kitab al-Hindusa which was rendered into Persian by one of his friends. "It had a large number of" says H. Suter, "geometrical problems for the fundamental construction of plane geometry to the constructions of the corners of a regular polyhedron on the circumscribed sphere of special interest is the fact that a number of these problems are solved by a single span of the compass, a condition which we find for the first time here."'

Nasir-ud-din Toosi, a great intellectual giant of Islam wrote Oawaid-ul-Hindasiya a book of geometry. Arabs were much in advance of Hindus and Greeks in the development and use of arithmetic, algebra and geometry.

Thabit bin Qurra is universally recognized as the greatest Muslim geometer. He was born in Harran and knew Greek and Syraic languages very well, so that he could read books of these countries in original. He wrote a number of short treatises on astronomy and mathematics. His treatise on Balance was translated into Latin by Gerard of Cremona. Al-Isfahani has contributed to conics. Isfahani also translated Greek works on Conics.


Trigonometry

It has been universally acknowledged that plane and spherical trigonometry were founded by Muslims who developed it considerably. The Greeks and other advanced nations of the ancient world were ignorant of this essential branch of mathematics.

Khwarizmi, the Muslim mathematician has made valuable contributions to this branch of mathematics also his trigonometrical tables which deal with the sine and tangent were translated into Latin in 1126 A. D. by Adelard of Bath.

Al-Battani (Latin Albategnius), the nation of trigonometrical ratios, which is now prevalent, owes its birth to the mathematical talents of Al-Battani. The third chapter, of his astronomical work, dealing with trigonometry, was several times translated into Latin and Spanish languages.

Jabir Bin Afiah is the author of the celebrated book Kitab Elahia which deals with astronomy and trigonometry. "His book Kitab Elahia says H. Suter, "is noteworthy for preparing the astronomical part with a special chapter on trigonometry. In his spherical trigonometry he takes the rule of the four magnitudes as the foundation for the deviations of his formulae and gives for the first time the fifth main formula of the right angled triangle."' His work was translated in Latin by Gerard of Cremona.

Abul Wafa (939--997, 998 A.D.) born at Buzjan in Khorasan later on established in Iraq was one of the greatest mathematicians that Islam has produced. He devoted himself to the researches in mathematics and astronomy. His Zijush Shamil (consolidated tables) are distinguished for their accurate observation and he introduced as well as popularized the use of the secant and tangent in trigonometry. "But this was not all" says Sedillot; "struck by the imperfection of the lunar theory of Ptolemy, he verified the ancient observations, and discovered, independently of the equation of the centre and the eviction, a third inequality, which is no other than the variation determined six centuries later by Tycho Brahe."' Abul Wafa was also an outstanding geometer who studied the quadrature of parabola and the volume of paraboloid. Writing in the Legacy of Islam, Carra de Vaux says, "Abul Wafa's services to trigonometry are indisputable. With him trigonometry becomes all the more explicit."" G. Sarton pays glowing tribute to the genius of this Muslim mathematician when he say’s, "Abul Wafa contributed considerably to the deve