Wednesday, 5 December 2012

Al-Sufi's Star Catalogue


A depiction of a Medieval Islamic astronomer. Thought by some to represent Abd al-Rahman al-Sufi.

The illustration above is a section of a painting showing workers at the observatory of Taqi al-Din at Istanbul in 1577. The particular painting is from the epic poem Shahinshah-nama by 'Ala ad-Din Mansur-Shiazi. It was written in honour of Sultan Murad III who reigned from 1574 to 1595. Though it is common to speak of Arabic astronomy the more correct term would be Arab-Islamic astronomy. Many of the astronomers (and peoples) were not Arabs but were from the regions of (modern-day) Iran, Iraq, and Afghanistan. Arabic was the scientific language and lingua franca for followers of the Islamic religion. The language of the religion was Arabic. It is correct to speak of Greek science being passed to the Arabs. Arab rulers of Arab states, for example the 'Umayyad dynasty (which collapsed in the 740s), funded and patronised the transmission process through Syriac sources. The 'Abbasid dynasty which followed can also be considered as an Arab regime.

A page from Al-Sufi's book on the constellations Kitab suwar al-kawakib (Book of the constellations of the Fixed Stars). The book was written for and dedicated to the Buwayhid ruler Fana Khusrau, titled Adud al-Dawla (made Emir of Iraq in 949 CE and died in 982 CE), who was a great patron of astronomy and had erected an observatory at Shiraz. Al-Sufi’s main source for his treatise is the star-catalogue compiled by the Alexandrian astronomer Ptolemy (called "BatlamiyUs" in Arabic). Ptolemy's star-catalogue was included in his major work Mathematika Syntaxis. In the preface to Kitab suwar al-kawakib, al-Sufi mentions that he referred to as many translations of the Almagest as he could find, having noticed discrepancies between them. Paul Kunitzsch has noted that al-Sufi's treatise mostly follows the wording of Isliaq b. Ijunayn's translation, but obtains star-positions from a range of versions.

Al-Sufi’s best known work is Kitab suwar al-kawakib (Book of the constellations of the Fixed Stars). "Fixed Stars" is a term describing the stars, which were thought to be fixed to the surface of a large celestial sphere, turning around the Earth. (The "Wandering Stars" are the planets, which were seen to move independently and at different paces, across the celestial sphere.)

Knowledge of the fixed stars in Greek-based Arab-Islamic astronomy was derived mainly from Ptolemy's Almagest which contained a catalogue of 1025 stars arranged in 48 constellations (circa 150 CE). The first critical revision of Ptolemy's catalogue of fixed stars was carried out by al-Sufi. However, al-Sufi adopted Ptolemy's basic scheme and pattern of constellations. He did not add or subtract stars from Ptolemy's star list and neither did he re-measure their (frequently incorrect) positions. Also, though al-Sufi based his constellation drawings (figures) on the classical Aratean tradition his figures have a distinct oriental character.

Arabic translations of Ptolemy’s Mathematika Syntaxis were made during the 9th- century, including those of Sahi al-Tabari, al-Hajjãj b. Yusuf b. Matar, and Isaq b. llunayn (died 877 CE), whose 827/828 CE version was later corrected by Thäbit b. Qurra (died 90 l CE).

Abd al-Rahman al-Sufi (Al-Sufi; known in Western Europe by the Latinized name Azophi) was born in 903 CE in Rayy (near modern Tehran), Persia and died in 986 CE. Al-Sufi lived and worked mostly in Isfahan (Persia) at the court of Emir Adud ad-Daula. (He worked in both Isfahan (Iran) and Baghdad (Iraq).) He is most widely known, and became most influential, for his translation and partial revision of Ptolemy's star catalogue as the Book of the constellations of the Fixed Stars (Kitab suwar al-kawakib). It was published circa 964 CE and it was frequently copied and translated. It had considerable influence on European astronomy.

Al-Sufi was both a translator and author. He was involved in translating Hellenistic astronomical works (that had been centred in Alexandria) into Arabic, especially Ptolemy's Almagest. He wrote numerous works on astronomical, astrological, and mathematical subjects. His most outstanding work is his illustrated book on the constellations (Kitab suwar al-kawakib). In this work he comprehensively describes the 48 classical constellations, which were established by Ptolemy and transmitted to the Islamic world in translations of Ptolemy's Almagest. Like all other Islamic scholars of the period he wrote all his works in Arabic (the scientific language of the Arab-Islamic world). In producing his own version of the star catalogue in Ptolemy's Almagest al-Sufi introduced many traditional Arabic star names. (Most star names used by al-Sufi (and his contemporaries) were direct translations of Ptolemy's descriptions.) It was the first attempt to relate (integrate/synthesise) the Greek stars of Ptolemy's star catalogue with the indigenous (traditional) Arabic star names and constellations (the Arab anwa tradition). Because some of the Arabic star names were centuries old their meanings were lost to al-Sufi and his contemporaries, and they remain unknown today. Another problem is that al-Sufi used anwa texts from the Islamic period as his sources. This somewhat limits their connection with indigenous pre-Islamic Arabic anwa traditions.

In Kitab suwar al-kawakib the description of each constellation comprises the following four sections: (1) A general discussion of the constellation and its individual stars. Also included in this section is al-Sufi's criticism of the Ptolemaic tradition and also notices of al-Sufi's own observations. (He described all the stars catalogued by Ptolemy and added his own criticism in each individual case.) (2) A record of the indigenous Arabic star names falling within each constellation, and the exact identification of each of these stars with the corresponding Ptolemaic stars. (3) Two drawings of the constellations, one depicting the constellation as it is seen on the celestial globe (i.e., as seen by an observer looking inwards towards earth), and the other one as it is seen in the sky (i.e., as seen by an observer looking outwards from earth). (4) A table of the stars making up each of the constellations, including a verbal description of each star's location and its longitude, latitude, and magnitude. (The magnitudes given were according to al-Sufi's own observations.) This table closely follows the arrangement of Ptolemy's star catalogue in the Almagest. In this book al-Sufi also described the boundaries of the constellations.

In al-Sufi's Kitab suwar al-kawakib the constellation figures and the individual stars comprising them are shown separately (i.e., separated from each other) without any information on their relative positions being given. No sky map (with all the constellations charted) appears in the book.

Al-Sufi's book on the constellations (and the constellation drawings contained in it) served as models for further work on the fixed stars in the Arab-Islamic world for many centuries. His description of the constellations became the basis for all later studies. (Al-Sufi's drawings of the constellation figures established a standard typology for the constellations.) Islamic constellation figures were introduced into Europe as least as early as the 13th-century. It is stated by some sources that al-Sufi's Kitab suwar al-kawakib was never translated into Latin. This is incorrect. A fully illustrated translation was (anonymously?) made in Palermo, Sicily, in the 12th-century at the instigation of Guillaumine II (1166-1189).the Norman king of Sicily. (A Latin manuscript of it, titled Liber de locis stellarum fixarum, now resides at the Arsenal Library in Paris as part of MS # 1036 (a collection of astronomical manuscripts with the general title Liber de stellis stellarum). The Liber de locis stellarum fixarum contains 49 illustrations representing the constellations and the signs of the zodiac. The Arabic-Persian iconography, based on characters in the One Thousand and One Nights story, is kept. The Parisian copy, made anonymously, is the oldest existing Latin copy. It is dated to the third quarter of the 13th-century and is believed to be a copy of the translation made earlier in Sicily. (It is sometimes identified as being made from a manuscript in Spain.) (The Holy Roman Emperor Frederick II, at his court in Palermo, Sicily, financed translations of Arabic works into Latin.) Al-Sufi's book was also fully translated into Spanish by Alfonso X ("Alfonso the Wise") of Leon and Castile, as Libros del Saber de Astronomia. It was through these translations that it influenced the star names of used in western Europe. Its contents were transmitted into Europe and in medieval Europe its constellation drawings were imitated in numerous Latin astronomical manuscripts.

Petrus Apianus (Peter Apian) (1495-1552) the 16th-century German astronomer and geographer took star names from al-Sufi's book on the constellations and placed them on his star charts and mentioned them in his writings. (See the chapter on the constellations in his Astronomicum Caesareum (1540).)

It has been long believed that al-Sufi's book on the constellations was the (exclusive) key source for the establishment of star names in western Europe. (Note: A few proper star names, such as Polaris (North Star), are not Arabic.) However, this now appears to be over-simplified and somewhat incorrect. The science historian Owen Gingerich writes ("Islamic Astronomy," Scientific American, Volume 254, April, 1986, Pages 68-?): "It now seems that his [i.e., Ptolemy's] 14th- and 15th-century Latin translators went to a Latin version of the Arabic edition of Ptolemy himself for the star descriptions, which they combined with al-Sufi's splendid pictorial representations of the constellations. Meanwhile the Arabic star nomenclature trickled into the West by another route: the making of astrolabes." (Some of these astrolabes have distorted Arabic names for stars.)

The astrolabe, essentially a two-dimensional model of the sky, was originally a Greek invention (dating circa 3rd-century BCE) to enable the problems of spherical astronomy (i.e., the prediction of star positions) to be solved. It moved with the spread of Islam through North Africa into Spain (Andalusia). It would appear that England, due to the scientific activity centred at Oxford, was the conduit for the introduction of the astrolabe from Spain into western Europe in the late 13th-century and the 14th-century.

Historians have not settled the debate over who was responsible for the transmission of the astrolabe from Muslim Spain into Europe and when and where the astrolabe first appeared in Europe. However, by 1030 CE at the latest some European scholars possessed astrolabes and were teaching their use. Early Christian recipients of Arab astronomy (including the astrolabe) included Gerbert of Aurillac and Hermannus Contractus. Gerbert of Aurillac (circa 946-1003 CE) (later to become Pope Sylvester II (999 - 1003 CE)) spent several years (967-969 CE) studying in Spain in the Christian-held city of Barcelona and also possibly in the Moorish-held cities of Córdoba and Seville. (He originally went to the cathedral school of Vic, in the province of Catalonia which was on the frontier of Moorish Spain. As a result there was considerable communication between Catalunya and the Muslims of al-Andalus to the south.) It is thought that Gerbert of Aurillac may have been the author of a description of the astrolabe ( The Book of the Astrolabe which was the first Latin text explaining the astrolabe and providing instructions for the construction of an astrolabe) that was edited by the Benedictine monk Hermannus Contractus (1013-1054 CE) some 50 years later.

Many of these early astrolabes that were introduced into Europe carried both Arabic and Latin star nomenclature. It has been noted by Paul Kunitzsch that star names that appear on medieval astrolabes in Europe are often quite different from star names that appear in star lists in medieval manuscripts. The astrolabe was widely used in Europe during the late Middle Ages and the Renaissance with its popularity peaking in the 15th- and 16th-centuries. (The astrolabes of the 11th-16th centuries were an important instrument for predicting star positions.) It became one of the basic astronomical education tools. Europeans eventually began to manufacture astrolabes. In the 15th-century European astrolabe manufacturing was centred in Augsberg and Nuremberg in Germany, with some manufacturing also in France. By the middle of the 17th-century astrolabes were being manufactured all over Europe.

(The astrolabe was a 'flattened' and more portable version of the armillary sphere. It was a two-dimensional representation of the celestial sphere and was used for solving problems in celestial geography.)

Islamic astronomical globes also became highly prized in medieval western Europe. Some were purchased and used without translation of Arabic terms as Arabic was a scientific language in medieval Europe. Some were purchased and copied with the names of stars and constellations being translated into Latin versions of Arabic. Arabic was frequently used on European globes along with other scientific languages. Globes were manufactured and used with astronomical terms in Latin, Greek, and Arabic.

European astronomers and celestial map makers began to use Arabic star names in preference to Latin names circa 12th-century CE. This practice kept on increasing with the increasing ease of European access to Islamic texts and instruments. By the end of the 15th-century the process of European adoption of Arabic star names was essentially complete. (According to Emilie Savage-Smith it has been established that a nearly complete Arabic version of al-Sufi's treatise on the constellations must have reached Germany by the 1530's, for information in it was employed in a limited way by Peter Apian, who from 1527 to 1552 was professor of mathematics at the University of Ingolstadt.) The "Arabic" names were retained in the formal, scientific nomenclature until the end of the 19th-century.

Al-Sufi's star catalogue was in turn revised by the the 15th-century Timurid governor (of Transoxiana and Turkestan) and astronomer Ulugh Beg, at his observatory in Samarkand, Uzbekistan. 

Tuesday, 27 November 2012

TRANSMISSION OF ISLAMIC ENGINEERING



Mechanical Engineering

Water-Raising Machines


The saqiya was widely used in the Muslim world from the earliest days onwards. It was introduced to the Iberian Peninsula by the Muslims, where it was massively exploited. Its Maximum expansion in the Valencian Country took place throughout the eighteenth century. In 1921 their number amounted to 6000 installed in the Orchards of Valencia, which supplied water to 17866 hectares. Throughout the twentieth century they have been replaced by hydraulic pumps.
                              A saqiva in Ma'arrat al-Nu'man near Aleppo

Today, this ancient water raising machine is seen in a few farming areas in the northern Mexican states. It also survives in the Yucatan Peninsula. It is reported that one group of farmers in Veracruz, Mexico is reverting back to using the traditional technology of the saqiya. 

The na'ura (noria) is also a very significant machine in the history of engineering. It consists of a large wheel made of timber and provided with paddles. The large-scale use of norias was introduced to Spain by Syrian engineers. An installation similar to that at Hama was in operation at Toledo in the twelfth century. 

The Na'ura (Noria) of Albolafia in Cordoba also known as Kulaib, which stands until now, served to elevate the water of the river until the Palace of the Caliphs. Its construction was commissioned by Abd al-Rahman I, and has been reconstructed several times.

                                                The Noria of Cordoba

The noria was heavily exploited all over Muslim Spain. It was diffused to other parts of Europe, and, like the Saqiya, has shown remarkable powers of survival into modern times. Five water-raising machines are described in al-Jazari's great book on machines, composed in Diyar Bakr in 1206. One of these is a water-driven saqiya, Three of the others are modifications to the shaduf. These are important for the ideas they embody, ideas which are of importance in the development of mechanical engineering as we shall mention below. The fifth machine is the most significant. This is a water-driven twin-cylinder pump. The important features embodied in this pump are the double-acting principle, the conversion of rotary into reciprocating motion, and the use of true suction pipes. The hand-driven pumps of classical and Hellenistic times had vertical cylinders which stood directly in the water which entered them through plate-valves in the bottoms of the cylinders on the suction strokes. The pumps could not, therefore, be positioned above the water level. This pump of al-Jazari could be considered as the origin of the suction pump. The assumption that Taccola (c. 1450) was the first to describe a suction pump is not substantiated. The only explanation for the sudden appearance of the suction pump in the writings of the Renaissance engineers in Europe is that the idea was inherited from Islam whose engineers were familiar with piston pumps for a long time throughout the Middle Ages.
                                 Twin Cylinder Suction Pump of Al-Jazari

Evidence for the continuation of a tradition of mechanical engineering is provided by a book on machines written by Taqi al-Din about the year 1552. A number of machines are described, including a pump similar to al-Jazari's, but the most interesting device is a six-cylinder 'Monobloc' pump. The cylinders are bored in-line in a block of wood which stands in the water - one-way valves admit water into each cylinder on the suction stroke. The delivery pipes, each of which is also provided with a one-way clack-valve, are led out from the side of each cylinder and brought together into a single delivery outlet. It is worthy of note that Taqi al-Din's book antedates the famous book on machines written by Agostino Ramelli in 1588. It is therefore quite possible that there was some Islamic influence on European machine technology even as late as the sixteenth century as we have alluded above.

Power from Water and Wind

The Muslim geographers and travelers leave us in no doubt as to the importance of corn-milling in the Muslim world. This importance is reflected by the widespread occurrence of mills from Iran to the Iberian Peninsula. Arab geographers were rating streams at so much 'mill-power'. Large urban communities were provided with flour by factory milling installations. 

The ship-mill was one of the methods used to increase the output of mills, taking advantage of the faster current in midstream and avoiding the problems caused by the lowering of the water level in the dry season. Another method was to fix the water-wheels to the piers of bridges in order to utilize the increased flow caused by the partial damming of the river. Dams were also constructed to provide additional power for mills (and water-raising machines) In the twelfth century al-Idrisi described the dam at Cordoba in Spain, in which there were three mill houses each containing four mills. Until quite recently its three mill houses still functioned.

 
Existing Mill Houses on a Dam Near Cordoba Were Described by al-Idrisi

Evidence of the Muslims' eagerness to harness every available source of water power is provided by their use of tidal mills in the tenth century in the Basra area where there were mills that were operated by the ebb-tide. Tidal mills did not appear in Europe until about a century after this. 

Water power was also used in Islam for other industrial purposes. In the year 751 the industry of paper-making was established in the city of Samarqand. The paper was made from linen, flax or hemp rags. Soon afterwards paper mills on the pattern of those in Samarqand were erected in Baghdad and spread until they reached Muslim Spain. The raw materials in these mills were prepared by pounding them with water-powered trip-hammers. Writing about the year 1044, al-Biruni tells us that gold ores were pulverized by this method "as is the case in Samarqand with the pounding of flax for paper". Water power was also used in the Muslim world for fulling cloth, sawing timber and processing sugarcane. It is yet to be established to what extent industrial milling in Europe was influenced by Muslim practices. A likely area of transfer is the Iberian Peninsula, where the Christians took over, in working order, many Muslim installations, including the paper mills at Jativa. 


ULASAN

Di antara sumbangan tamadun Islam dalam bidang sains dan teknologi adalah dalam bidang kejuruteraan mekanikal. bidang ini penting bagi menghasilkan alat-alat yang dapat memudahkan urusan seharian masyarakat ketika itu. sarjana Islam berjaya mencipta alat yang dikenali sebagai shaduf, noria atau naurah serta pam penyedut dua silinder bagi memudahkan kerja-kerja mengangkut air. Hal ini kerana air merupakan sumber terpenting pertanian serta keberlangsungan hidup.

حنين بن اسحاق

نسبه ومولده
هو أبو زيد حنين بن اسحق العبادي والعباد (بكسر العين وفتح الباء الخفيفة) من بطون القبائل العربية التي تنصرت في القرون الأولى للمسيحية, واستوطن قسم منها الحيرة وكانت تنتمي إلى كنيسة الشرق المسماة بالنسطورية, ثم سميت الأشورية والكلدانية ولد حنين في الحيرة سنة 194 هـ / 810 م0- ت260هـ / 3 م.وهي مدينة قديمة شهيرة وعاصمة اللخميين في جنوب العراق, فقد سكنوها منذ القرن الثالث الميلادي, وكلفهم الفرس الساسانيون بحراسة الحدود ضد هجمات الروم على بلاد ما بين النهرين السفلى, وهي من أشهر المدن العربية في القرون الثلاثة الأولى قبل الإسلام, وكان العباد يشكلون ثلث السكان فيها, وكانت تسمى حيرة النعمان أو حيرة المنذر واشتهرت بقصري الخورنق والسدير وانتشرت الأديار في أطرافها ومنها دير هند).  

يقول ابن القفطي أن والد حنين كان صيدلانيا وكانت الصيدلة حين ذاك تعني صناعة العقاقير من الحشائش والدراية بأمور الطب وفيها شيء من المتاجرة بالنقد واستبدال.
نشأته وتعلمه
 نشأ حنين في الحيرة (وليس في بغداد أو الشام كما جاء عند البيهقي وتأثر حنين بصناعة أبيه فمال إلى دراسة الطب وتعلم مبادئ العلوم في الحيرة مسقط رأسه وتمكن من السريانية لغة كنيسته حتى أنه لبس الزنار وصار شماسا. ثم درس الفارسية وصناعة الطب في أكاديمية جند يسابور المشهورة في خوزستان ببلاد فارس.وكانت معهدا أنشأه سابور الثاني أحد ملوك بني ساسان في أوائل القرن الرابع الميلادي وقد اشتهرت جنديسابور بيمارستانها ونبغ فيها آل بختيشوع.

ثم إن حنيناَ تخلص من ركاكة لغته المشوبة بألفاظ سريانية, بأن درس لغة الضاد في البصرة حتى برع فيها براعة يشهد بها المؤرخون, معتمدا في دراستها كتاب العين، للخليل بن أحمد الفراهيدي. وله الفضل في إدخال كتاب العين إلى بغداد. 

 يقال مثلا إنه نشأ في الحيرة ودرس فيها السريانية, ولبس الزنار (أي أصبح شماسا في الكنيسة) ثم ذهب إلى جند يسابور وتعلم الفارسية لكننا لا نعرف على وجه الدقة أين تعلم العربية ومن كان معلمه نتيجة للتضارب في أقوال   المؤرخين؛ يقول ابن القفطي:  إنه دخل البصرة ولزم الخليل بن احمد حتى برع في اللسان العربي؛  أما ابن جلجل فيقول: وكان الخليل بن أحمد النحوي رحمه الله، بأرض فارس فلزمه حنين حتى برع في لسان العرب.

في حين ينقل ابن أبي أصيبعة أن حنين بن اسحق كان يشتغل في العربية مع سيبويه وغيره ممن كانوا يشتغلون على الخليل بن أحمد الفراهيدي.

غير أنه يستحيل أن يكون حنين قد درس على الخليل بن أحمد المتوفي بين 170, 175 هجرية أي قبل أن يولد حنين بحوالي عشرين عاما.  

حيث ورد في عيون الأنباء عن الخليل بن أحمد بأنه :  
نحوي ولغوي،  أصله من عمان،  تعلم على أيوب السختياني،  وعلم سيبويه والأصمعي وغيرهما من أئمة اللغة،  وأكتشف علم العروض،  وتوفي في البصرة 180 هـ / 788 م؛  وأشهر كتبه العين. وفي بغداد لزم حنين بن اسحق الطبيب الشهير يوحنا بن ماسوية الجند يسابوري الأصل والمتوفي سنة 243/ 857؛ إذ ينقل ابن أبي أصيبعة؛عن يوسف بن إبراهيم  قوله:  أول ما حصل لحنين بن اسحق من الاجتهاد والعناية في صناعة الطب هو أن مجلس يوحنا بن ماسويه كان أعم مجلس في التصدي لتعليم الطب وكان يجتمع فيه أصناف أهل الأدب.

لم يستكمل حنين دراسته في بغداد لأنه أغضب أستاذه يوحنا بن ماسويه والسبب يرويه ابن القفطي وابن أبي أصيبعة؛  ومفاده أن حنيناً كان صاحب سؤال وكان يصعب على يوحنا إجابة كل أسئلته، وفي يوم من الأيام أحرجه بسؤال حول كتاب فرق الطب- فنهره يوحنا بغطرسة، ما لأهل الحيرة وتعلم بالطب،عليك ببيع القلوس على الطريق.

ويضيف ابن أبي أصيبعة أن حنينا كان من أبناء الصيارفة من أهل الحيرة وكان هذا أيضا يباعد بينه وبين يوحنا الجند يسابوري لأن أهل جند يسابور ومتطببوها يختلفون عن أهل الحيرة ويكرهون أن يدخل في صناعتهم أبناء التجار،  فأمره أن يخرج من داره، فترك حنين المجلس وخرج باكيا؛ وصمم على التحدي حتى يتفوق على الجميع، وأقسم أن يكون بريئا من دين النصرانية، إن هو رضي أن يتعلم الطب حتى يحكم اللسان اليونانى إحكاما لا يكون في دهره من يحكمه احكامه.

ويشهد المؤرخون ببراعة حنين في اللغة اليونانية، فيقول ابن جلجل: إن حنيناَ غدابارعا بلسان العرب، فصيحا جدا باللسان اليوناني، بارعا في اللسانين بلاغة بلغ بها تمييز علل اللسانين؛ إذ كان يعرف لغة اليونانيين معرفة تامة حتى أنه وضع كتابا في أحكام الإعراب على مذهب اليونانيين؛ ويؤكد البيهقي أن  لم يوجد في هذه الأزمنة بعد الإسكندر (الأفروديس) أعلم منه (أي من حنين) باللغة العربية واليونانية.

و كذلك الحال بالنسبة للغة اليونانية فلا يجزم أحد أين تعلمها ومتى، ولا نجد سوى بعض الاستنتاجات التي تقول إنه غاب خمس سنوات قضاها في بلاد الروم حيث تمكن من اللغة اليونانية والثقافية الهلينستية؛ في حين يتفق ابن القفطي وابن أبي أصيبعة في أنه دخل بلاد الروم للحصول على الكتب ولا يوجد تحديد لتاريخ دخوله أو خروجه.  




من كتاب ترجمة حنين بن اسحق للطب السرياني الى العربية (سنة 1205 ميلادي) 

شهرته في عصره
 عاد حنين إلى بغداد حوالي 211 هـ / 826م  وقد اكتسب  ثقافة رفيعة يستطيع أن يناقش بها أعظم المتعلمين في العاصمة العباسية فهو يمتلك زمام أربع لغات:  العربية والسريانية واليونانية والفارسية:  وهو ضليع بصناعة الطب مع الإلمام بالعلوم الأخرى الشائعة يومذاك, وهو متمكن من أسلوب نقدي صحيح في الترجمة وخبير بخفايا الثقافة الهللينستية, وقد كانت هي المشعل   المنير  لدروب المعرفة بشتى فروعها.

فلا عجب أن أخذ نجم حنين يتلألأ في الأوساط الثقافية ببغداد رغم صغر سنه إذ يروي ابن القفطيوابن أبي أصيبعة,  على لسان يوسف بن ابراهيم،  أنه كان يوما  عند اسحق بن الخصي، فرأى شخصا، قد جلله الشعر حتى ستر بعض وجهه، يتمشى وهو ينشد شعرا من أشعار هوميروس, فسأله عنه، وعرف أنه حنين غير أن حنين طلب منه ان يستر أمره, ثم مرت ثلاث سنوات على هذه الحادثة المذكورة, فكان يوسف عند جبرائيل بن بختيشوع الطبيب المتوفى (214هـ/ 829م) فوجد أن حنين قد ترجم أقساما  من كتاب التشريح لجالينوس وجبرائيل يمتدحه على ذلك ويبجله؛  فطلب حنين من يوسف أن يضع بين يدي يوحنا بن ماسويه معلمه السابق ترجمة له هي الفصول المسماه بالجوامع (الفاعلات) دون أن يخبره لمن الترجمة. ووفى يوسف بالوعد, فلما تصفح يوحنا الكتاب تعجب كثيرا  من دقة الترجمة, وفصاحتها و سأل هل أوحى المسيح لأحد من أبناء دهرنا فأجابه يوسف بانها لحنين بن اسحق, فسأله أن يصلح ما بينهما فتم ذلك. 






Eye Glasses in History

INTRODUCTION

Glasses - also called eyeglasses (formal) , spectacles, or specs (informal) - are frames Bearing lenses worn in front of the eyes, normally  for vision correction or eye Protection. Safety glasses are a kind of eye protection against flying debris or against Visible and near visible light or radiation.

Sunglasses allow better vision in bright Daylight, and may protect against damage from high levels of ultraviolet light. Other Types of glasses may be used for viewing visual information (such as stereoscopy) or Simply just for aesthetic or fashion values.

The word lens comes from the Latin name of the lentil , because a double-convex Lens is lentil-shaped. The genus of  the lentil plant is lens .and the most commonly Eaten species is lens culinaris. The lentil plant also gives its name to a geometric figure.
History of eyeglasses

Precursors
-Lenses in ancient Egypt
The earliest historical reference to magnification dates back to ancient
Egyptian hieroglyphs in the 5th century BC, which depict “simple glass
Meniscal lenses”. 

-Lenses in ancient Greece
The earliest written records of lenses data to Ancient Greece, with
Aristophanes’ play The Clouds (424 BC) mentioning a burning-glass
(a biconvex lens used to focus the sun’s rays to produce fire). 

-Lenses in ancient Roman
The earliest written record of magnification dates back to the 1 st centuries AD, when Seneca the Younger, a tutor of Emperor Nero of Rome, wrote: "Letters, however small and indistinct, are seen enlarged and more clearly through a globe or glass filled with water”.  Nero (reigned 54 – 68 AD) is also said to have watched the gladiatorial games using an emerald as a corrective lens. 
          
Figure 1: Emerald Ring                                   Figure 2: Emerald % 2520 Clarity.
Figure 3: Emerald % 255C Gallery                  Figure 4: Emerald stone
                 
                      

Figure 5: Crude Emerald.                                  Figure 6: Emerald Marine

                                             



                                                   Figure 7: Emerald 300X300


- Lenses in the 9th century

Corrective lenses were said to be used by Abbas Ibn Firnas in the 9th  century,  who had devised a way to produce very clear glass. These glasses could be shaped and polished into round rocks used for viewing and were known as reading stones.
Abbas Ibn Firnas (810 – 887 A.D.),also known as Abbas Qasim Ibn Firnas, Was a muslim Berber polymath: an inventor,  engineer, aviator,  physician,Arabic poet,and Andalusian musician. He was born in Izn-Rand Onda, Al-Andalus (today’s Ronda,Spain),and lived in the Emirate of Cordoba.He is known for an early attempt at aviation. 

Ibn Firnas designed a water clock called Al-Maqata,devised a means of manufacturing colorless glass, he invented various glass planispheres, Made corrective lenses(“reading stones”) , developed a chain of rings that could be used to simulate the motions of the planets and stars, and developed a process for cutting rock crystal that allowed Spain to cease exporting quartz to Egypt to be cut. 
Figure 8: Abbas Ibn Firnas, reading stone.

-Lenses in the 10th century

Ibn Sahl used what is now known as Snell’s law to calculate the shape of lenses. Ibn Sahl (c.940-1000)  was a Muslim Persian mathematician, Physicist and optics engineer of the Islamic Golden Age associated with The Abbasid court of Baghdad.Ibn Sahl’s 984 treatise On Burning Mirror and Lenses sets out his understanding of how curved mirrors and lenses bend and focus light. Ibn Sahl is credited with first discovering the law of refraction, usually called Snell’s Law. He used the law of refraction to derive lens shapes that focus light with no geometric aberration , known as anaclastic lenses.

                         
                                                Figure 9:  Ibn Sahl (Snell,s law).          
  
                                    Figure10:  Ibn Sahl,s work on refraction and optics


-Lenses in the 11th century

Widespread use of lenses did not occur until the use of reading stones in the 11 th century and the invention of spectacles, probably in Italy in the 1280s. Scholars have noted that spectacles were invented not long after the translation of Ibn al-Haytham’s  Book of Optics into Latin, but it is not clear what role,if any,the optical theory of the time played in the discovery.Ibn Sahl’s treatise was used by Ibn al-Haitham.

Abu Ali  al-Hasan  ibn al-Hasan  ibn al-Haytham(965 in Basra – c.1040 in cairo)  was a Persian  or Arab scientist and polymath.  He made significant contributions to the principles of optics, as well as to physics, anatomy, astronomy, engineering, mathematics, medicine,ophthalmology, philosophy, psychology, visual perception, and to science in general with his early application of the scientific method. He is sometimes called al-Basri, after his birthplace in the city of Basra.   He was also nicknamed Ptolemaeus Secundus (“Ptolemy the Second”) or simply “The Physicist” in medieval Europe. Alhazen wrote insightful comm -entaries on works by Aristotle, Ptolemy, and the Greek mathematician Euclid. 

Born circa 965, in Basra, Iraq and part of Buyid Persia at that time,  he lived mainly in Cairo, Egypt, dying there at age 76.   Over-confident about practical application of his mathematical knowledge, he assumed that he could regular the floods of the Nile. 

             Figure 11: Ibn Al-Haytham,s anatomy of the eye        
        

                                        Figure 12:Eye Diagram Ibn Al-Haytham


Figure 13: Optics (dated 1083):  Ibn al-Haytham's Optics, written in Eqypt in the first half of the 11th Century, represented a theory of vision that went beyond Galen, Euclid and Ptolemy. This diagram of the two eyes seen from above, shows the principal tunics and humours and the optic nerves connecting the eyeballs to the brain.
    
-Lenses in the 12th century

Sunglasses, in the form of flat panes of smoky quartz, protected the eyes from glare and were used in China in the 12th century or possibly earlier. Similarly, the Inuit have used snow goggles for eye protection. However, they did not offer any corrective benefits and the use by historians of the term "sunglasses" is anachronistic before the twentieth century.

                                       Figure 14: Smoky Quartz Gemstone.  


                           Figure 15: Smoky Quartz, Large loose  – 800X566.


                                       Figure 16: Smoky Quartz – 336X330.   

                                         Figure 17: Natural Smoky Quartz

 -Lenses in the 13th century

Englishman Robert Grosseteste's treatise De iride ("On the Rainbow"), written between 1220 and 1235, mentions using optics to "read the smallest letters at incredible distances". A few years later, Roger Bacon is also known to have written on the magnifying properties of lenses in 1262. Reportedly, spectacles were in use in China by the rich and elderly at the time of Marco Polo's arrival in 1270 or 1271, although the Chinese credit their invention to Arabia in the 11th century.

Invention of eyeglasses

Many theories abound for who should be credited for the invention of traditional eyeglasses. Despite evidence of spectacles in China in 1270, and Chinese claims of themselves importing spectacle technology from the Middle East in the 11th century, some people theorise that spectacles were first invented between 1280 and 1300 in Italy. Some also theorise that the first European inventor of spectacles was Salvino D'Armate.

In 1676, Francesco Redi, a professor of medicine at the University of Pisa, wrote that he possessed a 1289 manuscript whose author complains that he would be unable to read or write were it not for the recent invention of glasses. He also produced a record of a sermon given in 1305, in which the speaker, a Dominican friar named Fra Giordano da Rivalto, remarked that glasses had been invented less than twenty years previously, and that he had met the inventor. Based on this evidence, Redi credited another Dominican friar, Fra Alessandro da Spina of Pisa, with the re-invention of glasses after their original inventor kept them a secret, a claim contained in da Spina's obituary record However, Spina most likely learned to make spectacles after seeing them made by another individual, a talent for which he was known at the time.

Another potential inventor is Salvino D'Armate, who is credited with inventing the first wearable eye glasses on 16 September 1284 in Italy. In a 1684 history of Florence, Leopoldo del Migliore wrote that the church of Santa Maria Maggiore contained a memorial honoring D'Armati with the inscription: Here lies Salvino degl' Armati, son of Armato of Florence, inventor of eyeglasses. May God forgive his sins. A.D. 1317. The church has been rebuilt several times since the 13th century, however, and this tomb no longer exists, so the claim cannot be verified. Seated apostle holding lenses in position for reading. Detail from Death of the Virgin, by the Master of Heiligenkreuz, ca. 1400–30 (Getty Center).

The earliest pictorial evidence for the use of eyeglasses is Tommaso da Modena's 1352 portrait of the cardinal Hugh de Provence reading in a scriptorium. Another early example would be a depiction of eyeglasses found north of the Alps in an altarpiece of the church of Bad Wildungen, Germany, in 1403. 


These early spectacles had convex lenses that could correct both hyperopia (farsightedness), and the presbyopia that commonly develops as a symptom of aging. Nicholas of Cusa is believed to have discovered the benefits of concave lens in the treatment of myopia (nearsightedness). However, it was not until 1604 that Johannes Kepler published in his treatise on optics and astronomy, the first correct explanation as to why convex and concave lenses could correct presbyopia and myopia.