590 A L M A L M day; and now Baghdad became, under his auspices, the seat of academical instruction and the centre of intelli gence. At his own expense he caused to be translated into Arabic many valuable books from the Greek, Persian, Chaldean, and Coptic languages; and he was himself an ardent student of mathematics and astronomy. The first Arabic translation of Euclid was dedicated to him in 813. Mamun founded observatories at Baghdad and Kassiun (near Damascus) for astronomical purposes, and he suc ceeded in determining the inclination of the ecliptic. He also caused a degree of the meridian to be measured on the plain of Shinar; and he constructed astronomical tables, which are said to be wonderfully accurate. The supposed antagonism of orthodoxy and science receives some support from the conduct of Mamun. A lover of philosophy and letters, he did not concern himself about the creed of the professors he appointed to his colleges, or the physicians he employed at his court ; and on the occasion of his marriage he distributed largesses to Mussulmans, Jews, and Chris tians indiscriminately. These liberal measures culminated, however, in his becoming a convert in 827 to the heterodox faith of the Motasali, who asserted the free-will of man and denied the eternity of the Koran. The later years (829-830) of his reign were distracted by hostilities with the Greek emperor Theophilus, occasioned, it is said, by a dispute about an eminent Greek priest whom the caliph wished to attach to his college at Baghdad. A series of revolts in different parts of the Arabian empire be tokened the decline of the military glory of the caliphs. Already had Spain and part of Africa asserted their inde pendence, and Egypt and Syria were now inclined to follow. In 833, after quelling Egypt, at least nominally, Mamun marched into Cilicia to prosecute the war with the Greeks ; but with this expedition the career of one of the most famous of the caliphs was to terminate. He died near Tarsus, leaving his crown to a younger brother, Motassem. The death of Al-Mamun ended an important epoch in the history of science and letters, and the period of Arabian prosperity which his father s reign had begun. The in fluence of these two sovereigns is sometimes exaggerated; but there can be no doubt we owe much to their exertions at a time when Europe was sunk in barbarism. Mamun was the author of Inquiries into the Koran, of a tract on the Signs of Prophecy, and of one on the Rhetoric of the Priests and Panegyrists of the Caliphs. ALMANAC, a book or table, published from year to year, containing a calendar of the days, weeks, and months of the year, a register of ecclesiastical festivals and saints days, and a record of various astronomical phenomena, particularly the rising and setting of the sun, the changes and phases of the moon, eclipses of the sun and moon, the times of high water at particular ports, &c. In addition to these contents, which may be regarded as essential to the almanac, it generally presents additional information, which is more or less extensive and varied according to the many different special objects contemplated in works of this kind. The derivation of the word is doubtful. The first syllable is the Arabic definite article; the rest of the word has been variously derived from the Greek p.r)v, a month; the Anglo-Saxon mona, the moon; and (which appears the most probable derivation) the Arabic manah, to reckon. The CALENDAR will be treated of in a separate article (which see). Here we have to do with the publication which contains the calendar of any particular year, along with other matter, astronomical, statistical, political, &c. The JEphemeris again, it is to be observed, is a strict astronomical term, being a register from day to day of the places and motions of the heavenly bodies. The attention given to astronomy by Eastern nations, and the practice that prevailed among them of divination by means of the stars, must have led to the early con struction of such tables as are comprised in our almanacs. Our information respecting these is extremely scanty; but we are not left in the same ignorance with regard to the practice of the ancient Romans. The peculiar arrangement of their calendar is well known, and their fasti sacri or kalendares were very similar to modern almanacs. Origin ally knowledge of the calendar was confined to the class of pontifices or priests, whom the people had to consult not only about the dates of the festivals, but also regarding the proper times of instituting various legal proceedings. But about 300 B.C. one Cn. Flavius, the secretary of Appius Claudius, possessed him-self of the secret, either by the stealthy iise of documents in the possession of his master, or, according to Pliny, by repeatedly consulting the pontifices and jurists, and collating the particulars of the information he obtained from them. It was neither more nor less than publishing an almanac when, as Livy 1 relates, he exhibited the fasti on white tablets round the forum. From this time tablets containing the calendar, the festivals, astronomical phenomena, and sometimes historical notices, seem to have been common. The Fasti of Ovid is a poetical relation of incidents and traditions connected with the calendar. The researches of anti quaries have brought to light numerous fasti or cahndaria cut on marble and other kinds of stone. Representations of several of these will be found in G ruler s Inscriptiones. One figured there, the Farnese rustic calendar, is a cubical block of stone, on each of the four vertical faces of which three columns are engraved, detailing for each different month the number of days, the date of the nones, the lengths of the day and night, the sun s place in the zodiac (which is also indicated by a representation of the sign at the top of the column), the tutelary deity of the month, the rural operations of the season, and the chief festivals. Almanacs of a ruder kind, known as clogg almanacs, were in use in some parts of England as late as the end of the 1 7th century. Dr Robert Plot, keeper of the Ashmolean Museum and professor of chemistry at Oxford, gives a figure of one of these, with a very minute description, in his Natural History of Staffordshire (Oxford, 168G); and another is represented in Gough s edition of Camdeu 3 Britannia (1806, vol. ii. p. 499). The cloggs were square blocks of hard wood, about 8 inches in length, with notches along the four angles corresponding to the days of the year. The accompanying illustration shows the angle on which is registered the almanac for the mouths of January, February, and March, taking it from left to right. The marks on the under side in the figure exhibit the primes or golden numbers of a cycle, which is fuJly described in Plot s work. They generally increase by 8, 19 being struck off when that number is exceeded; and the same number will be found to stand against all the dates (approximately) of new moon throughout the year. The cross mark is for X, and the hook at the end of a line for V. The weeks are indicated by a deeper notch for every seventh day, and a broadening stroke on the upper side in the figure represents the first day of each month. 1 " Fastos circa forum in albo proposuit, ut quando lege agi posset,
sciretur" (ix. 46).
