I B Y -I C E 611 Michael, a large but ungainly building of grey sandstone, there are seven Greek churches, a Roman Catholic church, a Protestant church, a Jewish synagogue, and a church belonging to the strange Russian sect of the Lipovani or Skoptsi. Ibraila has long had a large share in the trade of the Danube. In 1836 it was visited by 382 ships. In 1870 there entered 4936 vessels and 6697 cleared, with a respective total burden of 867,189 tons and 821,274 tons. In 1877 the experts included 87,002 quarters of wheat, 87,314 of maize, 80,938 of barley, 11,964 of rye, besides a large quantity of grain which appears under the returns for Galatz. The railway between Ibraila and Galatz takes a wid? circuit, instead of following the direct line of the river. The population, according to Henke (Rumdnien : Land und Yolk, Leipsic, 1877), is 42,000, of whom 53 per cent, are Roumanians, 20 per cent. Greeks, 15 per cent. Jews, and the remainder Germans, &c. According to the Bidet, So;. Geoyr. R)m>me, 1876, the total is 28,000. In the latter part of the 18th century Ibraila was several times taken by the Russians, and on one occasion (1770) it was burned. By the peace of Bucharest (1812) the Turks retained the right of farrisoning the fortress. la 1828 it was gallantly defended by oilman Pasha, who, after holding out from the middle of May till the end of June, was allowed to march out with the honours of war. At the peace of Adrianople the place was definitively assigned to "Wallachia. It was the spot chosen by Gortschakoff for crossing the Danube with his division in 1854. IBYCUS, a Greek lyric poet, who flourished about the 60th Olympiad 540 B.C. was a native of Rhegiiun in Italy, but spent the greater part of his life at the court of Polycrates, tyrant of Samos. A curious story, not always accepted, is told in connexion with his death. While travelling in the neighbourhood of Corinth, the poet was waylaid and mortally wounded by robbers. As he lay dying on the ground, he saw a flock of cranes flying overhead, and called upon them to avenge his death. The murderers beto;>k themselves to Corinth, and soon after, while sitting in the theatre, saw the cranes hovering above. One of them, either in alarm or jest, ejaculated, " Behold the avengers of Ibycus," and thus gave the clue to the detection of the crime. The phrase, " the cranes of Ibycus," passed into a proverb among the Greeks. Of the seven books of lyrics by Ibycus, which Suidas mentions, only a few frag ments have come down to us, but these afford sufficient evidence to support Cicero s estimate of the author whom he pronounces (Tusc., iv. 33) from his writings " maxime vero omnium flagrasse amore." Even from his mythical and heroic pieces, in which he was less successful, Ibycus did not exclude the erotic element. The dialect in which he wrote partook both of the Doric and of the yEolic peculiarities. The best edition of the fragments is Ibyd Skegini Carminum Reliquirc, edited by Schneidewin, and published at Gottingen in 1833. ICA, Yc.v, or ECCA, an inland city of Peru, capital of a district in the department of Lima, situated 170 miles south-south-east of the city of Lima, and 48 miles south- south-west of Pisco on the Pacific Ocean, with which it is connected by a railway. Between Pisco and lea the country is a desolate and barren desert, but lea itself lies in a fruitful valley surrounded by corn-fields and vineyards. On account of the frequent earthquakes the town has a very ruinous appearance, but it enjoys considerable prosperity, and ex ports by way of Pisco large quantities of wheat, maize, cotton, co;hineal, wine, and spirits. Originally the city, when founded in 1563, was built 4 miles south-east from where it now stands, the change of site taking place after a great earthquake in 1571. Another severe earthquake in 1664 led to a new town being built close to the old one. The population is .about 7000. ICE is the solid crystalline form which water assumes when exposed to a sufficiently low temperature. It is frequently precipitated from the air as hoarfrost, snow, or huil; and in the glaciers and snows of lofty mountain sys tems or of regions of high latitude it exists on a gigantic scale, being especially characteristic of the seas and lands around the poles, which consequently have hitherto been practically inaccessible to man. Also in various parts of the world, especially in France and Italy, great quantities of ice form in caves, which, in virtue of their depth below the earth s surface, their height above the sea-level, or their exposure to suitable winds, or to two or more of these conditions in combination, are unaffected by ordinary climatic changes, so that the mean annual temperature is sufficiently low to ensure the permanency of the ice. The great ice supply for the island of Teneriffe is obtained from such a cave, which is 100 feet long, 30 feet broad, and from 10 to 15 feet high, and which is situated on the Peak some 10,000 feet above the sea-level. Accord ing to the Rev. S. Browne (Brit. Ass. Report, 1864), such cave-ice is generally peculiar in its columnar appear ance, and apparently less easy to melt than ordinary surface ice. In the mutual transformations of water and ice, many remarkable physical phenomena occur. Thus, during the process of melting a block of ice or of freezing a quantity I of water, no change of temperature can take place so long as
- there is a thorough mixture of water and ice. Consequently,
the " freezing-point" or temperature at which water freezes i is a temperature so readily determined that it is conveniently employed as one of the standard temperatures in the gradua tion of ordinary thermometer scales, such as the centigrade, i the Fahrenheit, and the Reaumur. The centigrade scale, whose zero corresponds to this freezing-point of water, is the temperature scale that is employed throughout this ! article. In the act of freezing, water, though its tempera- ture remains unchanged, undergoes a remarkable expansion or increase of bulk, so that ice at C. is less dense than water a fact demonstrated at once by its power of floating. "Ground-ice" or "anchor-ice," which forms in certain cir- cumstances at the bottom of streams, is only an apparent exception to this relation between the densities of water in its solid and liquid states, being retained there by the cohesion between it and the stones or rocks which compose the river s bed. When forcibly released from this contact with the bottom, the ice at once ascends to the surface. Ground-ice may thus be the lowest stratum of the once completely frozen mass of water, adhering to the bottom
- during the thawing and melting of the ice at the surface ;
or it may even be formed under favourable conditions below briskly flowing water, probably by the action of eddies, | which draw the surface water down through the warmer but denser liquid, and thus cool the stones and rocks at the bottom. As water then expands on freezing, so con versely ice contracts on melting; and the ice-cold water thus ! formed continues to contract when heated until it has | reached its point of maximum density. Joule, from a series | of careful experiments, determined the temperature at which water attains its maximum density to be 39 l Fahr., or very nearly 4 C. Hence water contracts as its temperature rises from C. to 4 C.; but at higher temperatures it behaves like the great majority of other substances, expand- ing with rise of temperature. At no temperature, however, i does water in the liquid state become less dense than ice, j as the following table of relative densities shows : Density of ice at 0. = 9)75 water at C. = 99988 4" C. = 1-00000 ,, 10 C. "99976 ,, 100 C. -95866 Under the influence of heat, ice itself behaves as most
solids do, contracting when cooled, expanding when heated.
