Batrachians (ba-trā´ki-anz; Gr. batrachŏs, a frog), the fourth order in Cuvier's arrangement of the class Reptilia, comprising frogs, toads, newts, salamanders, and sirens. The term is now sometimes employed as synonymous with amphibia, but is more usually restricted to the order Anura or tailless amphibia. See Amphibia.

Batshian. See Bachian.

Bat´ta, an allowance which military officers in India receive in addition to their pay. It was originally given only when the officers were on the march or in the field, but now half batta is paid when troops are in cantonments.

Battal´ion, the tactical unit of command in infantry, supposed to be of the maximum strength to be efficiently handled by one officer in chief command, with others under him. In most armies it is about 1000 to 1100 men. The former is about the strength of a battalion in the British army, in which battalions now correspond to what were formerly regiments, the chief commanding officer (in actual command) being the lieutenant-colonel. See Army.

Battalion of Death, the legion of Russian women and girls, belonging to all classes, organized in 1917 and commanded by the famous revolutionary Madame Botshkalova. The battalion took part in several engagements.

Bat´tas, or Battaks, a people belonging to the Malayan race inhabiting the valleys and plateaus of the mountains that extend longitudinally through the Island of Sumatra. They practise agriculture and cattle-rearing, and are skillful in various handicrafts; they have also a written literature and an alphabet of their own, their books treating of astrology, witchcraft, medicine, war, &c. They are under the rule of hereditary chieftains. In 1908 a Battak Institute was established at Leyden for the study of the Battak country, people, &c.

Bat´tenberg, a village in the Prussian province of Hesse-Nassau, from which the sons (by morganatic marriage) of Prince Alexander of Hesse, uncle of Louis, Grand-Duke of Hesse, the husband of Princess Alice of Britain, derived their titles of princes of Battenberg. One of them, Alexander, was Prince of Bulgaria from 1879 to 1886, and died in 1893. Another, Prince Henry, was married to Princess Beatrice of Great Britain in 1885, and died in 1896.

Battenberg, Prince Louis Alexander of, born 24th May, 1854, in Graz, son of Prince Alexander of Hesse. He became a naturalized British subject, entered the navy in 1868, and in 1884 married Princess Victoria, eldest daughter of Princess Alice Maud, Grand-Duchess of Hesse-Darmstadt, and second daughter of Queen Victoria. He became rear-admiral in 1904, was second admiral of the Mediterranean fleet from 1906 to 1908, commanded the Atlantic fleet from 1908 to 1910, the 3rd and 4th divisions of the Home fleet in 1911, and was appointed Second Sea Lord in Nov., 1911, and First Sea Lord in Dec., 1912, in succession to Sir Francis Bridgeman. In October, 1914, however, in consequence of a campaign against alien enemies which culminated in an attack in the Globe on the First Sea Lord, he tendered his resignation to Mr. Winston Churchill, then First Lord of the Admiralty, on the ground that his birth and parentage in some respects impaired his usefulness. In 1917 the king determined that those princes of his family who were his subjects and bore German names and titles should relinquish those titles and adopt British surnames, and Prince Louis adopted the title of Marquess of Milford Haven, and the surname of Mountbatten. He was the author of Men-of-war Names, their Meaning and Origin (1908). He was made a Privy Councillor in 1914, and was both a Civil and a Military Knight Grand Cross of the Bath. He died 11th Sept., 1921.

Battering-ram, an engine for battering down the walls of besieged places. The ancients employed two different engines of this kind—one suspended in a frame, the other movable on