and contraction caused by changes of solar heat. He contended that the ice, like the lead, is expanded by heat, and that, as it cannot on expansion move up the valley without overcoming the resistance of gravitation as well as of friction, it necessarily moves chiefly downward, in which direction gravitation co-operates. Contraction on the other hand must also tend to send the ice downward, for a larger part will move with the force of gravitation than against it. Dr Croll, objecting to Canon Mosely’s views that no observed alterna- tions of glacier temperature warrant the conclusion that the ice can be impelled downward by that cause, has proposed yet another explanation. He regards the motion of the ice of a glacier as molecular, resulting from the very conduc- tion of heat through the mass of the glacier. He contends that from the thermal conditions of glacier-ice its molecules will melt before their temperature can be raised. Any given molecule on melting will transmit its extra heat or part of it to the next molecule, which in turn may melt, and thus a wave of thaw will travel through the ice. But as each molecule loses its heat again it freezes, and in the act of solidification exerts an enormous pressure on the walls of the interstice into which while fluid it entered. Hence in proportion to the amount of heat received by it the ice is subjected to great molecular pressure. As the glacier cannot expand laterally on account of the walls of its channel, and as gravitation opposes its expansion up the valley, it necessarily finds relief by a downward move-
rnent—the direction in which gravitation co-operates.
See Dc Saussure‘s rug/«yrs dans les 4 lpcs, § 5-35; De Charpenticr, Essai sur lcs Gliccz'rrs, 1841; Agassiz, Etudes sur lv's Glaciers, 1840, Systémc Glar'z'airc, 1847 ; L'Abbé llendn, “ Theorie des Glaciers de la Savoic,” in 11km. Acml. Sa'roz'r', x., 1841, translated by G. Forbes and published 1875; J. D. Forbes, Travels in the Alps, 1843, Norway and its Glaciers, 1853, and Occasional Papers 01L Glaciers, 1859 ; Tyndall's Glacicrs of thc Alps, 1857; Mousson’s (-r'lrt-S'C’lfi‘ (er Jrl:t:cit, 1854 ; Mosely, Proc. 1303/. Son, 1869 ; (‘roll, Cliuuitc. (uul Time, 1875 ; J. Thomson, Free. Roy. Soc, 1856—7.
GLADBACH, usually called Bergisch-Gladbach, a town of Prussia, circle of Mulheim, government district of Cologne, is situated 8 miles NE. of the latter town. It possesses an iron foundry, and manufactories of paper, pasteboard, powder, percussion caps, nets, and machinery. lronstone, peat, and lime are found in the vicinity. The population in 1875 was 7030.
GLADBACH, or Mönchen-Gladbach, a flourishing and rapidly increasing manufacturing town of llhenish Prussia, capital of a circle in the government district of Dusseldorf, is situated 16 miles W.S.W. of the town of that name. It is one of the chief manufacturing seats of Rhenish Prussia, its principal industries being the spinning and weaving of cotton, the manufacture of silks, velvet, ribbons, and damasks, and dyeing and bleaching. There are also tanneries, tobacco mannfaetories, machine works, and foundries. The town possesses a chamber of commerce, a gymnasium, and a female school of the higher grade. There are an Evangelic 11 and three Catholic churches, one of which possesses a choir of 1250, a nave dating from the beginning of the 12th century, and a crypt of the 8th century. Gladbach existed before the time of Charlemagne, and a Benedictine monastery was founded near it in 972 by Archbishop Gero of Cologne. The population in 1855 was only 4398; but it had increased in 1658 to 13,965, in 1861 to 17,074, in 1871 to 26,354, and in 1875 to 31,062.
GLADIATORS, professional combatants with men or beasts in the Roman arena. That this form of spectacle, which is almost peculiar to Rome and the Roman provinces, was originally borrowed from Etruria is shown by various indications. On an Etruscan tomb discovered at Tarquinii there is a representation of gladiatorial games; the slaves employed to carry off the dead bodies from the arena wore masks representing the Etruscan Charon ,- aud we learn from Isidore of Seville that the name for a trainer of gladiators, lam'sla, is an Etruscan word meaning butcher or executioner. These games are evidently a survival of the practice of immolating slaves and prisoners on the tomb of illustrious chieftains, a practice recorded in Greek, Roman, and Scandinavian legends, and traceable even as late as this century in the Indian suttee. Even at Rome they were for a long time confined to funerals, and hence the older name for gladiators was bustimrii; but in the later days of the republic their original significance was forgotten, and they formed as indispensable a part of the public amusements as the theatre or the circus.
The first gladiators are said, on the authority of Yalerius Maximus, to have been exhibited at Rome in the Forum Boarium 264 b.c., by Marcus and Decimus Brutus at the funeral of their father. On this occasion only three pairs fought, but the taste for these games spread rapidly, and the number of combatants grew apace. In 174 b.c. Titus Flalnininus celebrated his father’s obsequies by a three days’ fight, in which 74 gladiators took part. Julius Caesar engaged such extravagant numbers for his zedileship, that his political opponents took fright, and carried a decree of the senate imposing a certain limit of numbers 3 but notwithstanding this restriction he was able to exhibit no less than 300 couples. During the later days of the republic the gladiators were a constant element of danger to the public peace. The more turbulent spirits among the nobility had each his band of gladiators to act as a body guard, and the armed troops of Clodius, Milo, and Catiline played the same part in Roman history as the armed retainers of the feudal barons or the condottieri of the Italian republics.
Under the empire, notwithstanding sumptuary enactments, the passion for the arena steadily increased. Augustus, indeed, limited the shows to two a year, and forbade a przetor to exhibit more than 120 gladiators, yet allusions in Horace and Persius show that 100 pairs was the fashionable number for private entertainments; and in the Marmor Ancyranum the emperor states that more than 10,000 men had fought during his reign. The imbecile Claudius was devoted to this pastime, and would sit from morning till night in his chair of state, descending now and then to the arena to coax or force the reluctant gladiators to resume their bloody work. Under Nero senators and even well-born women appeared as combatants ; and J uvenal hashanded down to eternal infamy the descendant of the Gracchi that appeared without disguise as a rctiarius, and begged his life from the secular, who blushed to conquer one so noble and so vile. Titus, whom his countrymen surnamed the Clement, ordered a show which lasted 100 days; and Trajan, in celebration of his triumph over Decebalus, exhibited 5000 pairs of gladiators. Domitian instituted venationcs by torchlight, and at the Saturnalia of 90 a.d. arranged a battle between dwarfs and women. Even as late as 200 a.d. an edict was passed forbidding women to fight. How widely the taste for these sanguinary spectacles extended through- out the Roman provinces is attested by monuments, inscrip- tions, and the remains of vast amphitheatres. From Britain to Syria there was not a town of any size that could not boast its arena and annual games. The following inscription copied from the pedestal of a statue shows the important part they played in provincial life:—“In four days, at Minturme, he showed eleven pairs of gladiators, who did not cease fighting till one half, all the most valiant men in Cam- pania, had fallen. You remember it well, noble fellow citizens.” After Italy, Gaul, North Africa, and Spain were most famous for their amphitheatres,‘ and Greece was the only Roman province where the institution never took root.
