MARBLEHEAD 116 MARCH or as Da Costa does, there are: (1) Marbles of one plain color, which may be black, white, ash, gray, brown, red, yel- low, blue, or green; (2) Marbles of two colors, which are simply the foregoing marbles variegated with other colors; (3) Marbles variegated with many colors; and (4) Marbles containing shells, corals, and other extraneous bodies. Some of the fossiliferous limestones furnish ex- cellent marbles. For instance, the encri- nital limestones of the Carboniferous for- mation have the fossils white in a dark gray or black matrix. Non-fossiliferous crystalline marbles, consisting of sedi- mentary calcareous strata, altered by metamorphism, also furnish good mar- bles. The statuary marble of Italy may be of this character. The purest kinds are used for statues, those less pure as building material. The Carrara and Parian marbles are of this type. Other marbles are the Verd Antique, the Fire Marble or Lumachelle, the Giallo Antico, Madreporic Marble, etc. The Grand Canon of the Colorado is lined in many places with magnificent marble of vari- ous colors. Elgin marbles, a collection of bassi- rilievi and fragments of statuary brought from the Parthenon at Athens to Eng- land by Lord Elgin in 1814. They were afterward purchased by the British Gov- ernment, and are now in the British Museum. They consist chiefly of the metopes, representing for the most part the combats of the Centaurs and La- pithae, and the statues of fragments of statues which ornamented the tympana of the pediments of the Parthenon, or Temple of Minerva. To those were added the frieze from the Temple of Nike Apteros, a series of casts from the Temple of Theseus, and the choragic monument of Lysicrates. MABBLEHEAD, a town and port of entry in Essex co., Mass.; on Massachu- setts bay and on the Boston and Maine railroad; 17 miles N. E. of Boston. It contains Abbot Hall with a public library and art gallery, a high school, improved waterworks. National banks, and weekly newspapers. There are 30 shoe factories, seed-growing and fisheries industries. Pop. (1910) 7,388; (1920) 7,324. MARBURG (mar'borc), a quaint old town in the Prussian province of Hesse- Nassau, situated on the Lahn, 50 miles N. of Frankfort; built on a terraced hill crowned by a castle dating from 1065. In its Rittersaal (1277-1312) was held in 1529 the conference between the Wit- tenberg and the Swiss reformers regard- ing the Lord's Supper. The fine Gothic Church of Elizabeth, with two towers 243 feet high, was built in 1235-1283 by the Teutonic Knights over the splendid shrine of St. Elizabeth and was thoroughly re- stored in 1850-1867. The university occupies new Gothic buildings of 1879; in 1914-1915 had 118 professors and teach- ers and 2,040 students in theology, juris- prudence, medicine, and philosophy. It was founded in 1527 in the Reformed in- terest by Philip the Magnanimous, Land- grave of Hesse. Pop. about 25,000. MARCASITE, a bisulphide of iron. The term includes several varieties of iron pyrites, which have been named after the form they present: viz., cellular pyrites, cockscomb pyrites, hepatic py- rites, or leberkies, etc. It is used in the manufacture of sulphur, sulphuric acid, and sulphate of iron; but not to so great an extent as the ordinary sulphide. MARCELLINUS (-sel-li'nus), a Pope and saint, succeeded Caius in 296. He signalized himself by his courage in a severe persecution. The Donatists charged him with having sacrificed to idols; from which accusation he was vindicated by Augustine. He died in 304. MARCELLTJS (-sel'lus), I., Pope, succeeded Marcellinus in 308. The Em- peror Maxentius banished him from Rome for excommunicating an apostate. He died in 310. MARCELLTJS II., succeeded Julius III. in 1555, but died a few weeks after his election. MARCELLUS, M. CLAUDIUS, a Ro- man general and member of one of the most eminent plebeian families. In his first consulship (222 B. G.) he defeated the Insubrian Gauls and slew with his own hand their king, Britomartus or Viridomarus. In the second Punic war Marcellus took command after the dis- aster of Cannae, and checked Hannibal at Nola, in Campania (216 B. C.) Again consul in 214 B. c, he gave a fresh im- pulse to the war in Sicily. The skill of Archimedes compelled him to regularly blockade the city of Sjrracuse. Famine, pestilence, and ultimately treachery on the part of the Spanish auxiliaries of the Syracusans, opened its gates (212 B. c), after which the remainder of Sicily was soon brought under the dominion of the Romans. In his fifth consulship, 208 B. c, he fell in a skirmish against Han- nibal. MARCH, a frontier or boundary of a territory; especially applied to the bound- aries or confines of political divisions, or to the country Ijdng near and about such; as, for example, the frontiers be- '^ tween England and Scotland, and Eng-
