FIRE, GREEK, a destructive eompo sition, used in war from the ith to the 13th century. When the Arabs besieged Constantinople in 669, the Greek archi tect Callinicus of Heliopolis, deserted from the caliph to the Greeks, and took with him a composition, which, by its wonderful struck terror into the enemy, and forced them to take to flight. Sometimes it was wrapped in flax attach ed to arrows andjavelins, and so thrown into the fortifications and other buildings of the enemy, to set them on fire. At other times it was used in throwing stone balls from iron or metallic tubes against the enetny. The receipt for the compo sition of the Greek fire was long supposed to be lost ; but the baron Von Armin of Munich has, it is said, discovered in it Lat in MS. of the 13th century, in the central library in that city, a dissertation on the Greek fire, which contains the receipt.
NT, in Script ure, denotes the great arch or expanse over our heads, in which are placed the atmosphere and the clouds, and in which the stars appear to be placed, and are really seen.—In the Ptolemaic astronomy, the firmament is the eighth henVP11 or sphere, with respect to the soven spheres of the planets which it surrounds. It is supposed to have two motions; a diurnal motion, given to it by the primuno mobile, from east to west about the poles of the ecliptic; and another opposite motion from west to east, which last it finishes, according to Tycho, in 25,912 years; according to Ptolemy, in 36,000; and according to Co pernicus, in 25,800 ; in which the fixed stars return to the same point, in which they were at the beginning. This period is commonly calk.I the Platonic, or great year.