Page:Collier's New Encyclopedia v. 07.djvu/547

LEFT BED SEA 461 REDSTART islands of organic formation mention may be made of the volcanic group lying in lat. 14° N., the largest of which, Jebel Zugur, is 10 miles long, 7 miles wide, and 2,074 feet in height; farther N., on the islet of Jebel Teir, is a volcano which was active till quite recently. A dangerous reef, the Daedalus, lies directly in the path of steamers in lat. 24%° N., and a lighthouse has been placed on it. The principal harbors on the Red Sea are Mocha, Hodeida, Lokeyyah, Jiddah, and Yenbo, on the Arabian coast, and Massowah, Khor Nowarat, and Suakim on the African coast. In ancient times the Red Sea was used as a means of communication by the Phoenicians and other maritime peoples, till the discovery of the route round the Cape of Good Hope diverted the traffic into another channel, only to be revived, however, on a much more extensive scale with the construction of the Suez Canal. The tides are very variable, depend- ing largely on the direction and force of the winds, which also to a great extent determine the direction and velocity of the surface currents. The hot climate is due to the almost cloudless sky, and consequent want of rain, the altitude of the sun, and the absence of rivers. The mean temperature of the air generally ranges between 70° and 94° F. during the day, though readings of over 100° are often registered in the shade; but during the night the temperature may fall to the freezing point, owing to radi- ation in the clear atmosphere. The pre- vailing wind on shore is N. N. W. almost universally, but from October to May S. S. E. winds prevail over the S. por- tions of the sea, a belt of calms and variable winds occurring in the central regions, while in the N. portions the usual N. N. W. winds are met with. Evaporation is very great, and the air over the water is always very moist in the summer; hurricanes are unusual, but rain squalls frequently occur with the S. winds, and moderate gales and sandstorms, called "dragons" in the popular language of the Arabs, are not uncommon. The temperature of the water below the surface decreases down to a depth of about 200 fathoms, from whence down to the bottom a mean temperature of about 71° is found all the year round; this agrees with the temperature condi- tions prevailing in the inclosed seas of ohe East Indies, for instance, according to the observations made on board the "Challenger," the depth at which the minimum temperature occurs (i. e., 200 fathoms in the Red Sea) indicating the depth of water over the barrier sepa- rating the sea from the open ocean. In Tol. VII— Cyc winter, in the N. part, the whole body of water from surface to bottom usually y has a mean temperature of 71°. The salinity of the water is almost constant at about 1.030 (ordinary ocean water is about 1.026), and this is due to the fact that no rivers flow into it, little rain falls, and the evaporation is excessive. It has been estimated that, were the Red Sea entirely inclosed, it would become a solid mass of salt in less than 2,000 years, but this is prevented by an inflow of water through the Strait of Bab-el-Mandeb, and it is also known that a current of very salt water flows out underneath the incoming surface current. The greatest depth in the Red Sea is about 1,200 fathoms, and the mean depth of the whole area about 375 fathoms. From the point of greatest depth, which is near the center, the bottom rises toward each end. Owing to the absence of rivers the deposits approach in char- acter those formed in the open ocean, being largely composed of Foraminifera, Pteropods, and other pelagic shells. The marine fauna and flora are extensive, and have been described by Haeckel and other naturalists ; it has been shown that a migration of the Red Sea and Mediter- ranean faunae is taking place along tho Suez Canal. The path by which the Israelites went out of Egypt was along the course of the valley called Wady Tumeilat, apparently an old arm of the Nile now silted up. The Lake of Ismailieh (Timsah) was then most prob- ably the head of the Gulf of Suez, but the exact point of passage of this arm of the sea still remains obscure. REDSHANK, a term applied to a Scotch Highlander having buskins of red deer skin, with the hair outward; used also in derision of his bare legs. lu ornithology, the Totanus calidris, toler- ably common over the greater part of Europe and Asia, from Iceland to China, retiring to the S. in winter. It derives its popular name from the color of the bare parts of its legs. The body i« about the size of a snipe's, but the red- shank, haang longer wings, legs, and neck, appears the larger bird. REDSTART, the Ruti cilia phcenictira; common in Europe and western Asia, migrating S. in the winter. Forehead pure white, throat black, upper surface dark gray; breast, sides, and tail bright rust-red. It nests usually in a hollow tree or in a hole in a wall or rock, and lays five to seven delicate greenish-blue eggs, sprinkled with faint spots of red. The black, or black-capped redstart, R. titys (or litis) is common on the Conti- nent, but has not the extended N. range of the common redstart. In the United 3»