YELLOWSTONE NATIONAL PARK, a remarkable region in the extreme N. W. corner of Wyoming; set apart by Congress for a National reservation in 1872. Its area was originally 3,575 square miles, to which Congress, in 1891, added a tract of nearly 2,000 square miles to the S. and E.—nearly all more than 6,000 feet above sea-level, and ris ing in the snow-covered mountains to 10,000 to 14,000 feet. Situated on the "Great Divide," its pine-clad mountains form the gathering ground for the head waters of large rivers flowing away to the Atlantic and Pacific Oceans, and for the sake of the rainfall and the rivers its forests are carefully preserved.
The mammoth hot springs are of a class with those in the geyser basin. The element of beauty enters into the forma tions from the deposits left by the water. These have been built up by ages of activity, and are in scalloped terraces. Their greatest activity is manifested at the base of Capitol Hill. on the pictures que bank of the Gardiner river. But there are unmistakable evidences of their activity for miles back, for cedar crowned mounds yet yield treasures to the tourist who seeks specimens with a well-directed spade. In walking over some of the terraces where the water has ceased to run, the formation sounds hollow underneath, the action of the elements having built the terraces at the expense of the limestone beds below the surface. Caverns have been found underneath the now inactive basins, which are resplendent with stalactite and stalagmite formations that glisten under the blaze of a torch with singular bril liancy.
YEMEN ("the land to the right of Mecca"), a district in the S. W. of Ara bia, bounded on the N. by Hedjas and on the E. by Hadramaut, and measuring about 400 miles in length by about 150 miles in breadth. At about 30 miles from the coast a range of wooded moun tains (rising occasionally to 6,000 and 8,000 feet) stretches along the whole length of the country. Between this range and the sea stretches the scorch ingly hot plain called Teharneh. Fur ther inland the country becomes an ele vated plateau. Though destitute of rivers, the whole region is very fertile, and coffee, tobacco, dates, gums, and spices are produced and exported in abundance. There are valuable pearl fisheries on the coast. The inhabitants are Arabs, but possess many distinctive characteristics, and are supposed to be descended from the ancient Sabans. The government rests with the different sheiks or tribal chiefs, among whom the Imaun of Sans, holds supreme authority. The principal towns are Sana, the capi tal, Mocha, and Hodeda Mareb. Aden is not now within the limits of Yemen. The Arabia Felix of the ancients, Yemen was conquered by the Abyssinians (A. n. 525) and Persians (597). In the year 628 it submitted to Mohammed, since the 16th century has been subject to Tur key, and after the extension of Turkish rule (1871-1873) was formed into a vila yet.