Since somewhat of the recent imperial institutions regulating the Army and the Household have been set down, I shall now record the excellent ordinances of that sagacious intellect that energizes the world.

THE connection of monetary transactions without fixity of date would slip from the grasp, and through forgetfulness and falsehood raise a tumult of strife; for this reason every community devises a remedy and fixes an epoch. Since thought fosters well-being and is an aid to facility (of action), to displace obsolete chronology and establish a new usage is a necessity of government. For this reason, the prince regent on the throne of felicity in the 29th year of the Divine Era,* for the purpose of refreshing that plea­sure-ground of dominion and revenue, directed its irrigation and rendered blooming and lush the palace-garden of the State.

Compassing events within a determinate time, the Persian calls māhroz (date); the Arab has converted this into múarrakh (chronicled), and thence “taríkh (date) is a household word. Some derive the Arabic from irákh, a wild bull. This conjugation of the measure of tāfa'íl* means, to polish. As ignorance of the time of an event grew less, it became dis­tinguished by this name. Some assert that it is transposed from ‘tákhír which is referring a late period to an antecedent age. Others understand it to be a limit of time wherein an event determines. They say “such a one is the táríkh of his tribe,” that is, from whom dates the nobility of his line.* It is commonly understood to be a definite day to which subsequent time is referred and which constitutes an epoch. On this account they choose a day distinguished by some remarkable event,* such as the birth of a sect, a royal accession, a flood or an earthquake. By considerable labour and the aid of fortune, by constant divine worship and the observance of times, by illumination of the understanding and felicity of destiny, by the gathering together of far-seeing intelligences and by varied knowledge especially in the exact sciences and the Almighty favour, observatories were built: wonderful upper and lower rooms with diversity of window and stair arose on elevated sites little affected by dust.

By this means and with the aid of instruments such as the armillary sphere and others double-limbed and bi-tubular,* and the quadrant of altitude,* the astrolabe, the globe and others, the face of astronomy was illumined and the computation of the heavens, the position of the stars, the extent of their orbits in length and breadth, their distance from each other and from the earth, the comparative magnitude of the heavenly bodies and the like were ascertained. So great a work without the daily increasing aus­piciousness of a just monarch and his abundant solicitude, is not to be accomplished. The gathering together of learned men of liberal minds is not achievable simply by means of ample wealth, and the philosophic treatises of the past and the institutions of the ancients cannot be secured without the most strenuous endeavours of the sovereign. With all this, thirty years are needed to observe a single revolution of the seven planets.* The longer the period and the greater the care bestowed upon a task, the more perfect its completion.

In this time-worn world of affliction Divine Providence has vouchsafed its aid to many who have attained considerable renown in these con­structions, such as Archimedes, Aristarchus and Hipparchus in Egypt, from whose time to the present, the 40th year of the divine era, 1769 years have elapsed*; such as Plotemy in Alexandria who flourished some 1410 years ago; as the Caliph Mámún in Baghdad, 790 years past, and Sind* bin 'Ali and Khálid* bin 'Abdul Malik al Marwazi 764 years since at Damascus. Hákim and Ibn* Aa´'lam also laid the foundations of an observatory at Baghdad which remained unfinished, 712 years, and Battáni* at Racca 654 years previous to this time. Three hundred and sixty-two solar years have passed since Khwájah* Naṣîr of Tús built another at Múrágha near Tabríz and 156 is the age of that of Mirza Ulugh Beg* in Samarkand.

Rasad signifies ‘watching’ in the Arabic tongue and the watchers, therefore, are a body who, in a specially-adapted edifice, observe the move­ments of the stars and study their aspects. The results of their investigations and their discoveries regarding these sublime mysteries are tabulated and reduced to writing. This is called an astronomical table (zíj). This word is an Arabicized form of the Persian,* zík which means the threads that guide the embroiderers in weaving brocaded stuffs. In the same way, an astronomical table is a guide to the astronomer in recognising the conditions of the heavens, and the linear extensions and columns, in length and breadth, resemble these threads. It is said to be the Arabic rendering of zih from the frequent necessity of its use, which the intelligent will understand. Some maintain it to be Persian, signifying a mason's rule, and as he, through its instrumentality determines the evenness of a building, so an astronomer aims at accuracy by means of this astronomical table.

Many men have left such compilations to chronicle their fame. Among these are the Canous of

1. Ma´ju´r the Turk.

There are two of this family whom Sédillot terms the Benon Amadjour, viz., <Arabic> Hammer-Purgstall makes them the same person but adds another name <Arabic> According to him, they were brothers, and the former was the author of the Canon called al Bedíá or “the Wonder­ful;” the latter of works on other astronomical tables with disputed titles. He appears to quote from the Fihrist and from Casiri who borrows from Ibn Jounis, but the Fihrist dis­tinctly states that Abu'l Ḥasan was the son not the brother of Ali b. Amajúr. Ibn Jounis speaks of Abu'l Ḳásim also, and as a native of Herat, <Arabic>, which evidently refers to his Turkish origin but mis-translated by Casiri and copied by Ham-Purgstall ‘descended from the Pharaohs.” (Sedillot. p. xxxix note). The Benou Ama­júr were astronomers of repute and made their observations between the years 885-933, leading the way to important discoveries. (Sed p. xxxv et seq).

2. Hipparchus.

3. Ptolemy.

4. Pythagoras.

5. Zoroaster.

6. Theon of Alexandria.

7. Sa´ma´t the Greek.

Another reading is Sábát (<Arabic>) but I cannot recognize nor trace the name satis­factorily. The epithet <Arabic> inclines me to believe the name to be that of a Greek astronomer in Islamic times.

8. Tha´bit-b-Kurrah b Hárún was a native of Ḥarrán, of the Sabean sect, and rose to eminence in medicine, mathematics and philosophy, born A. H. 221 (A. D. 836) died in A. H. 288 (A. D. 901). He was much favoured by the Caliph Al Mua'tadhid who kept him at Court as an astrologer. He wrote on the Spherics of Theodosius, and retranslated Euclid already turned into Arabic by Hunain-b-Isháḳ al Ibádi. He was also author of a work in Syriac on the Sabean doctrines and the customs and ceremonies of their adherents. Ibn Khall. D'Herb. Sedillot. p. xxv. et seq. For a list of his works, see the Fihrist, p. 272.

9. Husa´m b. Sina´n. (var. Shabán.)

I believe the first name to be an error. The Fihrist mentions a son of Sinán with the patronymic Abúl Ḥasan who is no doubt here meant. He was grandson of Thábit-b-Ḳurrah, and named also Thábit according to Ḍ'Herb. as well as Abúl Ḥasan after his grandfather. (Sedillot). Equally proficient in astronomy with his grandfather, he was also a celebrated physician and practised in Baghdad. He wrote a history of his own time from about A. H. 290 to his death in 360. Abúl Faraj speaks of it as an excellent work. See also Ibn Khall. De Slane. Vol. II. p. 289 and note 7. His father Sinán the son of Thábit-b-Kurrah, died at Baghdad A. H. 331. They were both Harranians, the last representatives of ancient Greek learning through whom Greek sciences were communicated to the illiterate Arabs. Sinán made a collection of meteo­rological observations called the Kitáb ul anwá, compiled from ancient sources, incor­porated by Albiruni in his Chronology, and thereby preserved to us the most complete Parapegma of the ancient Greek world. See Albirúni. Chronol. Sachau's Transl. p. 427. n.