430 WALKER WALKING LEAF he received an appointment in the Washing- ton observatory, where on Feb. 2, 1847, four months after the detection of the planet Nep- tune, he made the discovery that a star ob- served by Lalande in May, 1795, must in fact have been this planet. The prediction conse- quently made, that the recorded star would not be found in the heavens, was confirmed by Prof. Hubbard. The same discovery was made independently in Europe a few weeks later by an actual examination of the heavens through 270 square degrees, and confirmed by an examination of the original manuscripts of Lalande. From 1847 till his death Mr. Walker had charge of the longitude computations of the United States coast survey. With Prof. Bache he developed the method of determin- ing differences of longitude by telegraph, which was put into successful operation in 1849. WALKER, William, an American adventurer, born in Nashville, Tenn., May 8, 1824, exe- cuted at Trujillo, Honduras, Sept. 12, 1860. He studied both law and medicine, was a jour- nalist in Now Orleans and San Francisco, and practised law in Marysville, Cal. In July, 1833, he organized an expedition for the con- quest of Sonora, but failed for want of sup- plies, after taking possession of Lower Cali- fornia, and surrendered himself to the United States officials at San Diego. In May, 1854, he was tried at San Francisco for violation of the neutrality laws, and was acquitted. In 1855 some American speculators in Nicaragua in- duced Walker to interfere in the intestine troubles of that country, ostensibly in aid of the democratic party. He landed at Realejo on June 11 with 62 followers, was joined by a few natives, fought successfully at Rivas and Virgin bay, took possession of the city of Granada on Oct. 15, and by a treaty with Cor- ral, the opposing leader ; was made general- issimo. Corral was tried for treason by a court martial over which Walker presided, and shot Nov. 8. Recruits came from the United States, and on March 1, 1856, Walker had 1,200 men. War breaking out with Costa Rica, he was defeated at Guanacaste on March 20, but had the advantage in a second battle at Rivas on April 11, and hostilities ceased, lie now broke up the interoceanic transit route by confiscating the property and revoking the charter of the Vanderbilt steamship company. In June he caused himself to be elected presi- dent, and in September annulled by a decree the existing prohibition of slavery. His arbi- trary acts provoked a domestic insurrection, which was seconded by several surrounding states and by agents of the Vanderbilt com- pany; and after a series of battles, on May 1, 1857, he delivered himself up with 16 of his officers to Commander C/ H. Davis of the United States sloop of war St. Mary's, by whom he was conveyed to Panama. Thence he went to New Orleans, where he was put under bonds to keep the peace ; but in Novem- ber he was once more in Nicaragua. In De- cember Commodore Paulding, U. S. N., com- pelled him and his 132 men to surrender, and carried them to New York ; but President Buchanan's government declined to recognize Walker as a prisoner, on the ground of the illegality of his arrest on foreign soil. In October, 1858, he sailed with a new expe- dition from Mobile, in a vessel without a clearance, but was arrested at the mouth of the Mississippi, tried at Now Orleans, and ac- quitted. In June, 1860, he sailed with a small force from New Orleans to Trujillo, with the de- sign of making a revolution in Honduras. Ho failed, and was captured and shot. He pub- lished " The War in Nicaragua" (Mobile, 1860). WALKING LEAF, the common name for a North American fern, also called walking fern. It was formerly classed as a&plenium rhizo- phyllum, which name it still retains in Eu- ropean catalogues, but it is now placed in a separate genus ; the sort or fruit dots often come together in pairs and are confluent where they meet, appearing like one long fruit dot bent upon itself ; on this account it is called Walking Leaf (Camptosorus rhizophyllus). camptosorus (Gr. a//Tr($f, bent, and au/>6^ a heap), retaining the same specific name. It is one of the rare, or rather local ferns, found from New England westward to Wisconsin, and southward along the mountains to Georgia, on moist, shady, and usually limestone rocks. The evergreen fronds grow in tufts and are from 4 to 9 in. long, with a long stipe (like a leaf stalk), lanceolate, with a heart-shaped, auricled, or halberd-shaped base, and tapering above into a very long, slender, almost filiform point ; the upper surface dark green and smooth, tho under side netted with veins, to which are attached the long fruit dots, either singly or together in the manner already described. The tips of the attenuate fronds often strike root where they touch the ground, and new fronds are formed at some little distance from the old
