The following are also noteworthy:--

7. POMPEIO (1569-1616), a native of Corsica, who served under Alessandro

Farnese and the marquis of Spinola in the Low Countries, where he lost

an arm, and, from the artificial substitute which he wore, came to be

known by the sobriquet Bras de Fer. He also defended Crete against the

Turks; and subsequently was killed in a reconnaissance at Friuli. He

left in Italian a personal narrative of the war in Flanders, which has

been repeatedly published in a Latin translation (_Bellum Belgicum_,

Antwerp, 1609).

8. GIOVANNI (1513-1556), born in Candia, translator of Terence's

_Andria_ and _Eunuchus_, of Cicero's _In Verrem_, and of Virgil's

_Aeneid_, viii.

9. ORSATTO (1538-1603), Venetian senator, translator of the _Oedipus

Tyrannus_ of Sophocles and author of a collection of _Rime_, in

imitation of Petrarch. He is regarded as one of the latest

representatives of the classic Italian school.

10. GERONIMO, a Genoese, flourished during the latter half of the 16th

century. He translated the _Alcestis_ of Euripides and three of the

plays of Sophocles; and wrote two original tragedies, _Jephte_ and

_Christo in Passione_.

11. VINCENZO, who in the beginning of the 17th century built the Roman

palace and made the art collection which are still associated with his

name (see _Galleria Giustiniana_, Rome, 1631). The collection was

removed in 1807 to Paris, where it was to some extent broken up. In 1815

all that remained of it, about 170 pictures, was purchased by the king

of Prussia and removed to Berlin, where it forms a portion of the royal

museum.

GIUSTO DA GUANTO [JODOCUS, or JUSTUS, OF GHENT] (fl. 1465-1475), Flemish

painter. The public records of the city of Ghent have been diligently

searched, but in vain, for a clue to the history of Justus or Jodocus,

whom Vasari and Guicciardini called Giusto da Guanto. Flemish annalists

of the 16th century have enlarged upon the scanty statements of Vasari,

and described Jodocus as a pupil of Hubert Van Eyck. But there is no

source to which this fable can be traced. The registers of St Luke's

gild at Ghent comprise six masters of the name of Joos or Jodocus who

practised at Ghent in the 15th century. But none of the works of these

masters has been preserved, and it is impossible to compare their style

with that of Giusto. It was between 1465 and 1474 that this artist

executed the "Communion of the Apostles" which Vasari has described, and

modern critics now see to the best advantage in the museum of Urbino. It

was painted for the brotherhood of Corpus Christi at the bidding of

Frederick of Montefeltro, who was introduced into the picture as the

companion of Caterino Zeno, a Persian envoy at that time on a mission to

the court of Urbino. From this curious production it may be seen that

Giusto, far from being a pupil of Hubert Van Eyck, was merely a disciple

of a later and less gifted master, who took to Italy some of the

peculiarities of his native schools, and forthwith commingled them with

those of his adopted country. As a composer and draughtsman Giusto

compares unfavourably with the better-known painters of Flanders; though

his portraits are good, his ideal figures are not remarkable for

elevation of type or for subtlety of character and expression. His work

is technically on a level with that of Gerard of St John, whose pictures

are preserved in the Belvedere at Vienna. Vespasian, a Florentine

bookseller who contributed much to form the antiquarian taste of

Frederick of Montefeltro, states that this duke sent to the Netherlands

for a capable artist to paint a series of "ancient worthies" for a

library recently erected in the palace of Urbino. It has been

conjectured that the author of these "worthies," which are still in

existence at the Louvre and in the Barberini palace at Rome, was Giusto.

Yet there are notable divergences between these pictures and the

"Communion of the Apostles." Still, it is not beyond the range of

probability that Giusto should have been able, after a certain time, to

temper his Flemish style by studying the masterpieces of Santi and

_Melozzo_, and so to acquire the mixed manner of the Flemings and

Italians which these portraits of worthies display. Such an

assimilation, if it really took place, might justify the Flemings in the

indulgence of a certain pride, considering that Raphael not only admired

these worthies, but copied them in the sketch-book which is now the

ornament of the Venetian Academy. There is no ground for presuming that

Giusto ad Guanto is identical with Justus d'Allamagna who painted the

"Annunciation" (1451) in the cloisters of Santa Maria di Castello at

Genoa. The drawing and colouring of this wall painting shows that Justus

d'Allamagna was as surely a native of south Germany as his homonym at

Urbino was a born Netherlander.

GIVET, a town of northern France, in the department of Ardennes, 40 m.

N. by E. of Mezieres on the Eastern railway between the town and Namur.

Pop. (1906) town, 5110; commune, 7468. Givet lies on the Meuse about 1

m. from the Belgian frontier, and was formerly a fortress of

considerable importance. It is divided into three portions--the citadel

called Charlemont and Grand Givet on the left bank of the river, and on

the opposite bank Petit Givet, connected with Grand Givet by a stone

bridge of five arches. The fortress of Charlemont, situated at the top

of a precipitous rock 705 ft. high, was founded by the emperor Charles

V. in the 16th century, and further fortified by Vauban at the end of

the 17th century; it is the only survival of the fortifications of the

town, the rest of which were destroyed in 1892. In Grand Givet there are

a church and a town-hall built by Vauban, and a statue of the composer

Etienne Mehul stands in the fine square named after him. Petit Givet,

the industrial quarter, is traversed by a small tributary of the Meuse,

the Houille, which is bordered by tanneries and glue factories. Pencils

and tobacco-pipes are also manufactured. The town has considerable river

traffic, consisting chiefly of coal, copper and stone. There is a

chamber of arts and manufactures.

GIVORS, a manufacturing town of south-eastern France, in the department

of Rhone, on the railway between Lyons and St Etienne, 14 m. S. of Lyon.

Pop. (1906) 11,444. It is situated on the right bank of the Rhone, here

crossed by a suspension bridge, at its confluence with the Gier and the

canal of Givors, which starts at Grand Croix on the Gier, some 13 m.

distant. The chief industries are metal-working, engineering-construction

and glass-working. There are coal mines in the vicinity. On the hill

overlooking the town are the ruins of the chateau of St Gerald and of the

convent of St Ferreol, remains of the old town destroyed in 1594.

GJALLAR, in Scandinavian mythology, the horn of Heimdall, the guardian

of the rainbow bridge by which the gods pass and repass between earth

and heaven. This horn had to be blown whenever a stranger approached the

bridge.

GLABRIO. 1. MANIUS ACILIUS GLABRIO, Roman statesman and general, member

of a plebeian family. When consul in 191 B.C. he defeated Antiochus the

Great of Syria at Thermopylae, and compelled him to leave Greece. He

then turned his attention to the Aetolians, who had persuaded Antiochus

to declare war against Rome, and was only prevented from crushing them

by the intercession of T. Quinctius Flamininus. In 189 Glabrio was a

candidate for the censorship, but was bitterly opposed by the nobles. He

was accused by the tribunes of having concealed a portion of the Syrian

spoils in his own house; his legate gave evidence against him, and he

withdrew his candidature. It is probable that he was the author of the

law which left it to the discretion of the pontiffs to insert or omit

the intercalary month of the year.

Censorinus, _De die natali_, xx.; Macrobius, _Saturnalia_, i. 13;

index to Livy; Appian, _Syr._ 17-21.

2. MANIUS ACILIUS GLABRIO, Roman statesman and general, grandson of the

famous jurist P. Mucius Scaevola. When praetor urbanus (70 B.C.) he

presided at the trial of Verres. According to Dio Cassius (xxxvi. 38),

in conjunction with L. Calpurnius Piso, his colleague in the consulship

(67), he brought forward a severe law (Lex Acilia Calpurnia) against

illegal canvassing at elections. In the same year he was appointed to

supersede L. Lucullus in the government of Cilicia and the command of

the war against Mithradates, but as he did absolutely nothing and was

unable to control the soldiery, he was in turn superseded by Pompey

according to the provisions of the Manilian law. Little else is known of

him except that he declared in favour of the death punishment for the

Catilinarian conspirators.

Dio Cassius xxxvi. 14, 16. 24; Cicero, _Pro lege Manilia_, 2. 9;

Appian, _Mithrid_. 90.

GLACE BAY, a city and port of entry of Cape Breton county, Nova Scotia,

Canada, on the Atlantic Ocean, 14 m. E. of Sydney, with which it is

connected both by steam and electric railway. It is the centre of the

properties of the Dominion Coal Company (founded 1893), which produce

most of the coal of Nova Scotia. Though it has a fair harbour, most of

the shipping is done from Sydney in summer and from Louisburg in winter.

Pop. (1892) 2000; (1901) 6945; (1906) 13,000.

GLACIAL PERIOD, in geology, the name usually given, by English and

American writers, to that comparatively recent time when all parts of

the world suffered a marked lowering of temperature, accompanied in

northern Europe and North America by glacial conditions, not unlike

those which now characterize the Polar regions. This period, which is

also known as the "Great Ice Age" (German _Die Eiszeit_), is synchronous

with the Pleistocene period, the earlier of the Post-Tertiary or

Quaternary divisions of geological time. Although "Glacial period" and

"Pleistocene" (q.v.) are often used synonymously it is convenient to

consider them separately, inasmuch as not a few Pleistocene formations

have no causal relationship with conditions of glaciation. Not until the

beginning of the 19th century did the deposits now generally recognized

as the result of ice action receive serious attention; the tendency was

to regard such superficial and irregular material as mere rubbish. Early

ideas upon the subject usually assigned floods as the formative agency,

and this view is still not without its supporters (see Sir H. H.

Howorth, _The Glacial Nightmare and the Flood_). Doubtless this attitude

was in part due to the comparative rarity of glaciers and ice-fields

where the work of ice could be directly observed. It was natural

therefore that the first scientific references to glacial action should

have been stimulated by the Alpine regions of Switzerland, which called

forth the writings of J. J. Scheuchzer, B. F. Kuhn, H. B. de Saussure,

F. G. Hugi, and particularly those of J. Venetz, J. G. von Charpentier

and L. Aggasiz. Canon Rendu, J. Forbes and others had studied the cause

of motion of glaciers, while keen observers, notably Sir James Hall, A.

Brongniart and J. Playfair, had noted the occurrence of travelled and

scratched stones.

The result of these efforts was the conception of great ice-sheets

flowing over the land, grinding the rock surfaces and transporting rock

debris in the manner to be observed in the existing glaciers. However,

before this view had become established Sir C. Lyell evolved the "drift

theory" to explain the widely spread phenomenon of transported blocks,

boulder clay and the allied deposits; in this he was supported by Sir H.

de la Beche, Charles Darwin, Sir R. I. Murchison and many others.

According to the drift theory, the transport and distribution of

"erratic blocks," &c., had been effected by floating icebergs; this view

naturally involved a considerable and widespread submergence of the

land, an assumption which appeared to receive support from the

occasional presence of marine shells at high levels in the "drift"

deposits. So great was the influence of those who favoured the drift

theory that even to-day it cannot be said to have lost complete hold; we

still speak of "drift" deposits in England and America, and the belief

in one or more great submergences during the Glacial period is still

held more firmly by certain geologists than the evidence would seem to

warrant. The case against the drift theory was most clearly expressed by

Sir A. C. Ramsay for England and Scotland, and by the Swedish scientist

Otto Torell. Since then the labours of Professor James Geikie, Sir

Archibald Geikie, Professor P. Kendall and others in England; von

Verendt, H. Credner, de Geer, E. Geinitz, A. Helland, Jentzsch, K.

Keilhack, A. Penck, H. Schroder, F. Wahnschaffe in Scandinavia and

Germany; T. C. Chamberlin, W. Upham, G. F. Wright in North America, have

all tended to confirm the view that it is to the movement of glaciers

and ice-sheets that we must look as the predominant agent of transport

and abrasion in this period. The three stages through which our

knowledge of glacial work has advanced may thus be summarized: (1) the

diluvial hypothesis, deposits formed by floods; (2) the drift

hypothesis, deposits formed mainly by icebergs and floating ice; (3) the

ice-sheet hypothesis, deposits formed directly or indirectly through the

agency of flowing ice.

_Evidences._--The evidence relied upon by geologists for the former

existence of the great ice-sheets which traversed the northern regions

of Europe and America is mainly of two kinds: (1) the peculiar erosion

of the older rocks by ice and ice-borne stones, and (2) the nature and

disposition of ice-borne rock debris. After having established the

criteria by which the work of moving ice is to be recognized in regions

of active glaciation, the task of identifying the results of earlier

glaciation elsewhere has been carried on with unabated energy.

[Illustration: Glacial period.]

1. _Ice Erosion._--Although there are certain points of difference

between the work of glaciers and broad ice-sheets, the former being more

or less restricted laterally by the valleys in which they flow, the

general results of their passage over the rocky floor are essentially

similar. Smooth rounded outlines are imparted to the rocks, markedly

contrasting with the pinnacled and irregular surfaces produced by

ordinary weathering; where these rounded surfaces have been formed on a

minor scale the well-known features of _roches moutonnees_ (German

_Rundhocker_) are created; on a larger scale we have the erosion-form

known as "crag and tail," when the ice-sheet has overridden ground with

more pronounced contours, the side of the hill facing the advancing ice

being rounded and gently curved (German _Stossseite_), and the opposite

side (_Leeseite_) steep, abrupt and much less smooth. Such features are

never associated with the erosion of water. The rounding of rock

surfaces is regularly accompanied by grooving and striation (German

_Schrammen, Schliffe_) caused by the grinding action of stones and

boulders embedded in the moving ice. These "glacial striae" are of great

value in determining the latest path of the vanished ice-sheets (see

map). Several other erosion-features are generally associated with ice

action; such are the circular-headed valleys, "cirques" or "corries"

(German _Zirkus_) of mountain districts; the pot-holes, giants' kettles

(_Strudellocher_, _Riesentopfe_), familiarly exemplified in the

Gletschergarten near Lucerne; the "rock-basins" (_Felsseebecken_) of

mountainous regions are also believed to be assignable to this cause on

account of their frequent association with other glacial phenomena, but

it is more than probable that the action of running water (waterfalls,

&c.)--influenced no doubt by the disposition of the ice--has had much

to do with these forms of erosion. As regards rock-basins, geologists

are still divided in opinion: Sir A. C. Ramsay, J. Geikie, Tyndall,

Helland, H. Hess, A. Penck, and others have expressed themselves in

favour of a glacial origin; while A. Heim, F. Stapff, T. Kjerulf, L.

Rutimeyer and many others have strongly opposed this view.

2. Glacial deposits may be roughly classified in two groups: those that

have been formed directly by the action of the ice, and those formed

through the agency of water flowing under, upon, and from the

ice-sheets, or in streams and lakes modified by the presence of the ice.

To differentiate in practice between the results of these two agencies

is a matter of some difficulty in the case of unstratified deposits; but

the boulder clay may be taken as the typical formation of the glacier or

ice-sheet, whether it has been left as a _terminal moraine_ at the limit

of glaciation or as a _ground moraine_ beneath the ice. A stratified

form of boulder clay, which not infrequently rests upon, and is

therefore younger than, the more typical variety, is usually regarded as

a deposit formed by water from the material (_englacial_, _innenmoran_)

held in suspension within the ice, and set free during the process of

melting. Besides the innumerable boulders, large and small, embedded in

the boulder clay, isolated masses of rock, often of enormous size, have

been borne by ice-sheets far from their original home and stranded when

the ice melted. These "erratic blocks," "perched blocks" (German

_Findlinge_) are familiar objects in the Alpine glacier districts, where

they have frequently received individual names, but they are just as

easily recognized in regions from which the glaciers that brought them

there have long since been banished. Not only did the ice transport

blocks of hard rock, granite and the like, but huge masses of stratified

rock were torn from their bed by the same agency; the masses of chalk in

the cliffs near Cromer are well known; near Berlin, at Firkenwald, there

is a transported mass of chalk estimated to be at least 2,000,000 cubic

metres in bulk, which has travelled probably 15 kilometres from its

original site; a block of Lincolnshire oolite is recorded by C.

Fox-Strangways near Melton in Leicestershire, which is 300 yds. long and

100 yds. broad if no more; and instances of a similar kind might be

multiplied.

When we turn to the "fluvio-glacial" deposits we find a bewildering

variety of stratified and partially bedded deposits of gravel, sand and

clay, occurring separately or in every conceivable condition of

association. Some of these deposits have received distinctive names;

such are the "Kames" of Scotland, which are represented in Ireland by

"Eskers," and in Scandinavia by "Asar." Another type of hillocky deposit

is exemplified by the "drums" or "drumlins." Everywhere beyond the

margin of the advancing or retreating ice-sheets these deposits were

being formed; streams bore away coarse and fine materials and spread

them out upon alluvial plains or upon the floors of innumerable lakes,

many of which were directly caused by the damming of the ordinary

water-courses by the ice. As the level of such lakes was changed new

beach-lines were produced, such as are still evident in the great lake

region of North America, in the parallel roads of Glen Roy, and the

"Strandlinien" of many parts of northern Europe.

Viewed in relation to man's position on the earth, no geological changes

have had a more profound importance than those of the Glacial period.

The whole of the glaciated region bears evidence of remarkable

modification of topographic features; in parts of Scotland or Norway or

Canada the old rocks are bared of soil, rounded and smoothed as far as

the eye can see. The old soil and subsoil, the product of ages of

ordinary weathering, were removed from vast areas to be deposited and

concentrated in others. Old valleys were filled--often to a great depth,

300-400 ft.; rivers were diverted from their old courses, never to

return; lakes of vast size were caused by the damming of old outlets

(Lake Lahontan, Lake Agassiz, &c., in North America), while an infinite

number of shifting lakelets--with their deposits--played an important

part along the ice-front at all stages of its career. The influence of

this period upon the present distribution of plant and animal life in

northern latitudes can hardly be overestimated.

Much stress has been laid upon supposed great changes in the level of

the land in northern regions during the Glacial period. The occurrence

of marine shells at an elevation of 1350 ft. at Moel Tryfaen in north

Wales, and at 1200 ft. near Macclesfield in Cheshire, has been cited as

evidence of profound submergence by some geologists, though others see

in these and similar occurrences only the transporting action of

ice-sheets that have traversed the floor of the adjoining seas. Marine

shells in stratified materials have been found on the coast of Scotland

at 100 ft. and over, in S. Scandinavia at 600 to 800 ft., and in the

"Champlain" deposits of North America at various heights. The dead

shells of the "Yoldia clay" cover wide areas at the bottom of the North

Atlantic at depths from 500 to 1300 fathoms, though the same mollusc is

now found living in Arctic seas at the depth of 5 to 15 fathoms. This

has been looked upon as a proof that in the N.W. European region the

lithosphere stood about 2600 ft. higher than it does now (Brogger,

Nansen, &c.), and it has been suggested that a union of the mainland of

Europe with that of North America--forming a northern continental mass,

"Prosarctis"--may have been achieved by way of Iceland, Jan Mayen Land

and Greenland. The pre-glacial valleys and fjords of Norway and

Scotland, with their deeply submerged seaward ends, are regarded as

proofs of former elevation. The great depth of alluvium in some places

(236 metres at Bremen) points in the same direction. Evidences of

changes of level occur in early, middle and late Pleistocene formations,

and the nature of the evidence is such that it is on the whole safer to

assume the existence only of the more moderate degree of change.

_The Cause of the Glacial Period._--Many attempts have been made to

formulate a satisfactory hypothesis that shall conform with the known

facts and explain the great change in climatic conditions which set in

towards the close of the Tertiary era, and culminated during the Glacial

period. Some of the more prominent hypotheses may be mentioned, but

space will not permit of a detailed analysis of theories, most of which

rest upon somewhat unsubstantial ground. The principal facts to be taken

into consideration are (1) the great lowering of temperature over the

whole earth; (2) the localization of extreme glaciation in north-west

Europe and north-east America; and (3) the local retrogression of the

ice-sheets, once or more times repeated.

Some have suggested the simple solution of a change in the earth's axis,

and have indicated that the pole may have travelled through some 15 deg.

to 20 deg. of latitude; thus, the polar glaciation, as it now exists,

might have been in this way transferred to include north-west Europe and

North America; but modern views on the rigidity of the earth's body,

together with the lack of any evidence of the correlative movement of

climatic zones in other parts of the world, render this hypothesis quite

untenable. On similar grounds a change in the earth's centre of gravity

is unthinkable. Theories based upon the variations in the obliquity of

the ecliptic or eccentricity of the earth's orbit, or on the passage of

the solar system through cold regions of space, or upon the known

variations in the heat emitted by the sun, are all insecure and

unsatisfactory. The hypothesis elaborated by James Croll (_Phil. Mag._,

1864, 28, p. 121; _Climate and Time_, 1875; and _Discussion on Climate

and Cosmology_, 1889) was founded upon the assumption that with the

earth's eccentricity at its maximum and winter in the north at aphelion,

there would be a tendency in northern latitudes for the accumulation of

snow and ice, which would be accentuated indirectly by the formation of

fogs and a modification of the trade winds. The shifting of the thermal

equator, and with it the direction of the trade winds, would divert some

of the warm ocean currents from the cold regions, and this effect was

greatly enhanced, he considered, by the configuration of the Atlantic

Ocean. Croll's hypothesis was supported by Sir R. Ball (_The Cause of

the Great Ice Age_, 1893), and it met with very general acceptance; but

it has been destructively criticized by Professor S. Newcomb (_Phil.

Mag._, 1876, 1883, 1884) and by E. P. Culverwell (_Phil. Mag._, 1894,

p. 541, and _Geol. Mag._, 1895, pp. 3 and 55). The difficulties in the

way of Croll's theory are: (1) the fundamental assumption, that

midwinter and midsummer temperatures are directly proportional to the

sun's heat at those periods, is not in accordance with observed facts;

(2) the glacial periods would be limited in duration to an appropriate

fraction of the precessional period (21,000 years), which appears to be

too short a time for the work that was actually done by ice agency; and

(3) Croll's glacial periods would alternate between the northern and

southern hemispheres, affecting first one then the other. Sir C. Lyell

and others have advocated the view that great elevation of the land in

polar regions would be conducive to glacial conditions; this is

doubtless true, but the evidence that the Glacial period was primarily

due to this cause is not well established. Other writers have

endeavoured to support the elevation theory by combining with it various

astronomical and meteorological agencies. More recently several

hypotheses have been advanced to explain the glacial period as the

result of changes in the atmosphere; F. W. Harmer ("The Influence of

Winds upon the Climate during the Pleistocene Epoch," _Q.J.G.S._, 1901,

57, p. 405) has shown the importance of the influence of winds in

certain circumstances; Marsden Manson ("The Evolution of Climate,"

_American Geologist_, 1899, 24, p. 93) has laid stress upon the

influence of clouds; but neither of these theories grapples successfully

with the fundamental difficulties. Others again have requisitioned the

variability in the amount of the carbon dioxide in the

atmosphere--hypotheses which depend upon the efficiency of this gas as a

thermal absorbent. The supply of carbon dioxide may be increased from

time to time, as by the emanations from volcanoes (S. Arrhenius and A.

G. Hogbom), or it may be decreased by absorption into sea-water, and by

the carbonation of rocks. Professor T. C. Chamberlin based a theory of

glaciation on the depletion of the carbon dioxide of the air ("An

Attempt to frame a Working Hypothesis of the cause of Glacial Periods on

an Atmospheric Basis," _Jl. Geol._, 1899, vii. 752-771; see also

Chamberlin and Salisbury, _Geology_, 1906, ii. 674 and iii. 432). The

outline of this hypothesis is as follows: The general conditions for

glaciation were (1) that the oceanic circulation was interrupted by the

existence of land; (2) that vertical circulation of the atmosphere was

accelerated by continental and other influences; (3) that the thermal

blanketing of the earth was reduced by a depletion of the moisture and

carbon dioxide in the atmosphere, and that hence the average temperature

of the surface of the earth and of the body of the ocean was reduced,

and diversity in the distribution of heat and moisture introduced. The

localization of glaciation is assignable to the two great areas of

permanent atmospheric depression that have their present centres near

Greenland and the Aleutian Islands respectively. The periodicity of

glacial advances and retreats, demanded by those who believe in the

validity of so-called "interglacial" epochs, is explained by a series of

complicated processes involving the alternate depletion and completion

of the normal charge of carbon dioxide in the air.

Whatever may be the ultimate verdict upon this difficult subject, it is

tolerably clear that no simple cause of glacial conditions is likely to

be discovered, but rather it will appear that these conditions resulted

from the interaction of a complicated series of factors; and further,

until a greater degree of unanimity can be approached in the

interpretation of observed facts, particularly as regards the

substantiality of interglacial epochs, the very foundations of a sound

working hypothesis are wanting.

_Classification of Glacial Deposits--Interglacial Epochs._--Had the

deposits of glaciated regions consisted solely of boulder clay little

difficulty might have been experienced in dealing with their

classification. But there are intercalated in the boulder clays those

irregular stratified and partially stratified masses of sand, gravel and

loam, frequently containing marine or freshwater shells and layers of

peat with plant remains, which have given rise to the conception of

"interglacial epochs"--pauses in the rigorous conditions of glaciation,

when the ice-sheets dwindled almost entirely away, while plants and

animals re-established themselves on the newly exposed soil. Glacialists

may be ranged in two schools: those who believe that one or more phases

of milder climatic conditions broke up the whole Glacial period into

alternating epochs of glaciation and "deglaciation"; and those who

believe that the intercalated deposits represent rather the _localized_

recessional movements of the ice-sheets within one single period of

glaciation. In addition to the stratified deposits and their contents,

important evidence in favour of interglacial epochs occurs in the

presence of weathered surfaces on the top of older boulder clays, which

are themselves covered by younger glacial deposits.

The cause of the interglacial hypothesis has been most ardently

championed in England by Professor James Geikie; who has endeavoured

to show that there were in Europe six distinct glacial epochs within

the Glacial period, separated by five epochs of more moderate

temperature. These are enumerated below:

6th Glacial epoch, Upper Turbarian, indicated by the deposits of peat

which underlie the lower raised beaches.

5th _Interglacial epoch, Upper Forestian_.

5th Glacial epoch, Lower Turbarian, indicated by peat deposits

overlying the lower forest-bed, by the raised beaches and carse-clays

of Scotland, and in part by the _Littorina_-clays of Scandinavia.

4th _Interglacial epoch, Lower Forestian_, the lower forests under

peat beds, the _Ancylus_-beds of the great freshwater Baltic lake and

the _Littorina_-clays of Scandinavia.

4th Glacial epoch, Mecklenburgian, represented by the moraines of the

last great Baltic glacier, which reach their southern limit in

Mecklenburg; the 100-ft. terrace of Scotland and the _Yoldia_-beds of

Scandinavia.

3rd _Interglacial epoch, Neudeckian_, intercalations of marine and

freshwater deposits in the boulder clays of the southern Baltic

coasts.

3rd Glacial epoch, Polandian, glacial and fluvio-glacial formations of

the minor Scandinavian ice-sheet; and the "upper boulder clay" of

northern and western Europe.

2nd _Interglacial epoch, Helvetian_, interglacial beds of Britain and

lignites of Switzerland.

2nd Glacial epoch, Saxonian, deposits of the period of maximum

glaciation when the northern ice-sheet reached the low ground of

Saxony, and the Alpine glaciers formed the outermost moraines.

1st _Interglacial epoch, Norfolkian_, the forest-bed series of

Norfolk.

1st Glacial epoch, Scanian, represented only in the south of Sweden,

which was overridden by a large Baltic glacier. The Chillesford clay

and Weybourne crag of Norfolk and the oldest moraines and

fluvio-glacial gravels of the Arctic lands may belong to this epoch.

In a similar manner Professor Chamberlin and other American geologists

have recognized the following stages in the glaciation of North

America:

The Champlain, marine substage.

The Glacio-lacustrine substage.

The later Wisconsin (6th glacial).

_The fifth interglacial._

The earlier Wisconsin (5th glacial)

_The Peorian (4th interglacial)._

The Iowan (4th glacial).

_The Sangamon (3rd interglacial)._

The Illinoian (3rd glacial).

_The Yarmouth or Buchanan (2nd interglacial)._

The Kansan (2nd glacial).

_The Aftonian (1st interglacial)._

The sub-Aftonian or Jerseyan (1st glacial).

Although it is admitted that no strict correlation of the European and

North American stages is possible, it has been suggested that the

Aftonian may be the equivalent of the Helvetian; the Kansan may

represent the Saxonian; the Iowan, the Polandian; the Jerseyan, the

Scanian; the early Wisconsin, the Mecklenburgian. But considering how

fragmentary is much of the evidence in favour of these stages both in

Europe and America, the value of such attempts at correlation must be

infinitesimal. This is the more evident when it is observed that there

are other geologists of equal eminence who are unable to accept so

large a number of epochs after a close study of the local

circumstances; thus, in the subjoined scheme for north Germany, after

H. W. Munthe, there are three glacial and two interglacial epochs.

/ The _Mya_ time = beech-time.

Post-Glacial epoch < The _Littorina_ time = oak-time.

\ The _Ancylus_ time = pine- and birch-time.

/ Including the upper boulder clay,

| "younger Baltic moraine" with the

3rd Glacial " < _Yoldia_ or _Dryas_ phase in the

\ retrogressive stage.

2nd _Interglacial_ epoch including the _Cyprina_-clay.

2nd Glacial epoch, the maximum glaciation.

1st _Interglacial epoch_.

1st Glacial epoch, "older boulder clay."

Again, in the Alps four interglacial epochs have been recognized;

while in England there are many who are willing to concede one such

epoch, though even for this the evidence is not enough to satisfy all

glacialists (G. W. Lamplugh, Address, Section C, _Brit. Assoc._, York,

1906).

This great diversity of opinion is eloquent of the difficulties of the

subject; it is impossible not to see that the discovery of

interglacial epochs bears a close relationship to the origin of

certain hypotheses of the cause of glaciation; while it is significant

that those who have had to do the actual mapping of glacial deposits

have usually greater difficulty in finding good evidence of such

definite ameliorations of climate, than those who have founded their

views upon the examination of numerous but isolated areas.

_Extent of Glacial Deposits._--From evidence of the kind cited above,

it appears that during the glacial period a series of great ice-sheets

covered enormous areas in North America and north-west Europe. The

area covered during the maximum extension of the ice has been reckoned

at 20 million square kilometres (nearly 8 million sq. m.) in North

America and 6-1/2 million square kilometres (about 2-1/2 million sq.

m.) in Europe.

In Europe three great centres existed from which the ice-streams

radiated; foremost in importance was the region of Fennoscandia (the

name for Scandinavia with Finland as a single geological region); from

this centre the ice spread out far into Germany and Russia and

westward, across the North Sea, to the shores of Britain. The southern

boundary of the ice extended from the estuary of the Rhine in an

irregular series of lobes along the Schiefergebirge, Harz,

Thuringerwald, Erzgebirge and Riesengebirge, and the northern flanks

of the Carpathians towards Cracow. Down the valley of the Dnieper a

lobe of the ice-sheet projected as far as 40 deg. 50' N.; another lobe

extended down the Don valley as far as 48 deg. N.; thence the boundary

runs north-easterly towards the Urals and the Kara Sea. The British

Islands constituted the centre second in importance; Scotland, Ireland

and all but the southern part of England were covered by a moving

ice-cap. On the west the ice-sheets reached out to sea; on the east

they were conterminous with those from Scandinavia. The third European

centre was the Alpine region; it is abundantly clear from the masses

of morainic detritus and perched blocks that here, in the time of

maximum glaciation, the ice-covered area was enormously in excess of

the shrivelled remnants, which still remain in the existing glaciers.

All the valleys were filled with moving ice; thus the Rhone glacier at

its maximum filled Lake Geneva and the plain between the Bernese

Oberland and the Jura; it even overrode the latter and advanced

towards Besancon. Extensive glaciation was not limited to the

aforesaid regions, for all the areas of high ground had their

independent glaciers strongly developed; the Pyrenees, the central

highlands of France, the Vosges, Black Forest, Apennines and Caucasus

were centres of minor but still important glaciation.

The greatest expansion of ice-sheets was located on the North American

continent; here, too, there were three principal centres of outflow:

the "Cordilleran" ice-sheet in the N.W., the "Keewatin" sheet,

radiating from the central Canadian plains, and the eastern "Labrador"

or "Laurentide" sheet. From each of these centres the ice poured

outwards in every direction, but the principal flow in each case was

towards the south-west. The southern boundary of the glaciated area

runs as an irregular line along the 49 deg. parallel in the western

part of the continent, thence it follows the Mississippi valley down

to its junction with the Ohio (southern limit 37 deg. 30' N.),

eastward it follows the direction of that river and turns

north-eastward in the direction of New Jersey. As in Europe, the

mountainous regions of North America produced their own local

glaciers; in the Rockies, the Olympics and Sierras, the Bighorn

Mountains of Wyoming, the Uinta Mountains of Utah, &c. Although it was

in the northern hemisphere that the most extensive glaciation took

place, the effects of a general lowering of temperature seem to have

been felt in the mountainous regions of all parts; thus in South

America, New Zealand, Australia and Tasmania glaciers reached down the

valleys far below the existing limits, and even where none are now to

be found. In Asia the evidences of a former extension of glaciation

are traceable in the Himalayas, and northward in the high ranges of

China and Eastern Siberia. The same is true of parts of Turkestan and

Lebanon. In Africa also, in British East Africa moraines are

discovered 5400 ft. below their modern limit. In Iceland and

Greenland, and even in the Antarctic, there appears to be evidence of

a former greater extension of the ice. It is of interest to note that

Alaska seems to be free from excessive glaciation, and that a

remarkable "driftless" area lies in Wisconsin. The maximum glaciation

of the Glacial period was clearly centred around the North Atlantic.

_Glacial Epochs in the Older Geological Periods._--Since Ramsay drew

attention to the subject in 1855 ("On the occurrence of angular,

subangular, polished and striated fragments and boulders in the

Permian Breccia of Shropshire, Worcestershire, &c., and on the

probable existence of glaciers and icebergs in the Permian epoch,"

_Q.J.G.S._, 1855, pp. 185-205), a good deal of attention has been paid

to such formations. It is now generally acknowledged that the

Permo-carboniferous conglomerates with striated boulders and polished

rock surfaces, such as are found in the Karoo formation of South

Africa, the Talkir conglomerate of the Salt Range in India, and the

corresponding formations in Australia, represent undeniable glacial

conditions at that period on the great Indo-Australian continent. A

glacial origin has been suggested for numerous other conglomeratic

formations, such as the Pre-Cambrian Torridonian of Scotland, and

"Geisaschichten" of Norway; the basal Carboniferous conglomerate of

parts of England; the Permian breccias of England and parts of Europe;

the Trias of Devonshire; the coarse conglomerates in the Tertiary

Flysch in central Europe; and the Miocene conglomerates of the

Ligurian Apennines. In regard to the glacial nature of all these

formations there is, however, great divergence of opinion (see A.

Heim, "Zur Frage der exotischen Blocke in Flysch," _Eclogae geologicae

Helvetiae_, vol. ix. No. 3, 1907, pp. 413-424).

AUTHORITIES.--The literature dealing directly with the Glacial period

has reached enormous dimensions; in addition to the works already

mentioned the following may be taken as a guide to the general outline

of the subject: J. Geikie, _The Great Ice Age_ (3rd ed., London,

1904), also _Earth Sculpture_ (1898); G. F. Wright, _The Ice Age in

North America_ (4th ed., New York, 1905) and _Man and the Glacial

Period_ (1892); F. E. Geinitz, _Die Eiszeit_ (Braunschweig, 1906); A.

Penck and E. Bruckner, _Die Alpen im Eiszeitalter_ (Leipzig,

1901-1906, uncompleted). Many references to the literature will be

found in Sir A. Geikie's _Textbook of Geology_, vol. ii. (4th ed.,

1903); Chamberlin and Salisbury, _Geology_, vol. iii. (1906). As an

example of glacial theories carried beyond the usual limits, see M.

Gugenhan, _Die Ergletscherung der Erde von Pol zu Pol_ (Berlin, 1906).

See also _Zeitschrift fur Gletscherkunde_ (Berlin, 1906 and onwards

quarterly); Sir H. H. Howorth (opposing accepted glacial theories),

_The Glacial Nightmare and the Flood_, i., ii. (London, 1893), _Ice

and Water_, i., ii. (London, 1905), _The Mammoth and the Flood_

(London, 1887). (J. A. H.)

GLACIER (adopted from the French; from _glace_, ice, Lat. _glacies_), a

mass of compacted ice originating in a snow-field. Glaciers are formed

on any portion of the earth's surface that is permanently above the

snow-line. This line varies locally in the same latitudes, being in some

places higher than in others, but in the main it may be described as an

elliptical shell surrounding the earth with its longest diameter in the

tropics and its shortest in the polar regions, where it touches

sea-level. From the extreme regions of the Arctic and Antarctic circles

this cold shell swells upwards into a broad dome, from 15,000 to 18,000

ft. high over the tropics, truncating, as it rises, a number of peaks

and mountain ranges whose upper portions like all regions above this

thermal shell receive all their moisture in the form of snow. Since the

temperature above the snow-line is below freezing point evaporation is

very slight, and as the snow is solid it tends to accumulate in

snow-fields, where the snow of one year is covered by that of the next,

and these are wrapped over many deeper layers that have fallen in

previous years. If these piles of snow were rigid and immovable they

would increase in height until the whole field rose above the zone of

ordinary atmospheric precipitation, and the polar ice-caps would add a

load to these regions that would produce far-reaching results. The

mountain regions also would rise some miles in height, and all their

features would be buried in domes of snow some miles in thickness. When,

however, there is sufficient weight the mass yields to pressure and

flows outwards and downwards. Thus a balance of weight and height is

established, and the ice-field is disintegrated principally at the

edges, the surplus in polar regions being carried off in the form of

icebergs, and in mountain regions by streams that flow from the melting

ends of the glaciers.

_Formation._--The formation of glaciers is in all cases due to similar

causes, namely, to periodical and intermittent falls of snow. After a

snow-fall there is a period of rest during which the snow becomes

compacted by pressure and assumes the well-known granular character seen

in banks and patches of ordinary snow that lie longest upon the ground

when the snow is melting. This is the _firn_ or _neve_. The next fall of

snow covers and conceals the neve, but the light fresh crystals of this

new snow in turn become compacted to the coarsely crystalline granular

form of the underlying layer and become neve in turn. The process goes

on continually; the lower layers become subject to greater and greater

pressure, and in consequence become gradually compacted into dense clear

ice, which, however, retains its granular crystalline texture

throughout. The upper layers of neve are usually stratified, owing to

some individual peculiarity in the fall, or to the accumulation of dust

or debris upon the surface before it is covered by fresh snow. This

stratification is often visible on the emerging glacier, though it is

to be distinguished from the foliation planes caused by shearing

movement in the body of the glacier ice.

_Types._--The snow-field upon which a glacier depends is always formed

when snow-fall is greater than snow-waste. This occurs under varying

conditions with a differently resulting type of glacier. There are

limited fields of snow in many mountain regions giving rise to long

tongues of ice moving slowly down the valleys and therefore called

"valley glaciers." The greater part of Greenland is covered by an

ice-cap extending over nearly 400,000 sq. m., forming a kind of enormous

continuous glacier on its lower slopes. The Antarctic ice region is

believed to extend over more than 3,000,000 sq. m. Each of these

continental fields, besides producing block as distinguished from tongue

glaciers, sends into the sea a great number of icebergs during the

summer season. These ice-caps covering great regions are by far the most

important types. Between these "polar" or "continental glaciers" and the

"alpine" type there are many grades. Smaller detached ice-caps may rest

upon high plateaus as in Iceland, or several tongues of ice coming down

neighbouring valleys may splay out into convergent lobes on lower ground

and form a "piedmont glacier" such as the Malaspina Glacier in Alaska.

When the snow-field lies in a small depression the glacier may remain

suspended in the hollow and advance no farther than the edge of the

snow-field. This is called a "cliff-glacier," and is not uncommon in

mountain regions. The end of a larger glacier, or the edge of an

ice-sheet, may reach a precipitous cliff, where the ice will break from

the edge of the advancing mass and fall in blocks to the lower ground,

where a "reconstructed glacier" will be formed from the fragments and

advance farther down the slope.

When a glacier originates upon a dome-shaped or a level surface the ice

will deploy radially in all directions. When a snow-field is formed

above steep valleys separated by high ridges the ice will flow downwards

in long streams. If the valleys under the snow-fields are wide and

shallow the resultant glaciers will broaden out and partially fill them,

and in all cases, since the conditions of glacier formation are similar,

the resultant form and the direction of motion will depend upon the

amount of ice and the form of the surface over which the glacier flows.

A glacier flowing down a narrow gorge to an open valley, or on to a

plain, will spread at its foot into a fan-shaped lobe as the ice spreads

outwards while moving downwards. An ice-cap is in the main thickest at

the centre, and thins out at the edges. A valley glacier is thickest at

some point between its source and its end, but nearer to its source than

to its termination, but its thickness at various portions will depend

upon the contour of the valley floor over which the glacier rides, and

may reach many hundreds of feet. At its centre the Greenland ice-cap is

estimated to be over 5000 ft. thick. In all cases the glacier ends where

the waste of ice is greater than the supply, and since the relationship

varies in different years, or cycles of years, the end of a glacier may

advance or retreat in harmony with greater or less snow-fall or with

cooler or hotter summers. There seems to be a cycle of inclusive

contraction and expansion of from 35 to 40 or 50 years. At present the

ends of the Swiss glaciers are cradled in a mass of moraine-stuff due to

former extension of the glaciers, and investigations in India show that

in some parts of the Himalayas the glaciers are retreating as they are

in North America and even in the southern hemisphere (_Nature_, January

2, 1908, p. 201).

_Movement._--The fact that a glacier moves is easily demonstrated; the

cause of the movement is pressure upon a yielding mass; the nature of

the movement is still under discussion. Rows of stakes or stones placed

in line across a glacier are found to change their position with respect

to objects on the bank and also with regard to each other. The posts in

the centre of the ice-stream gradually move away from those at the side,

proving that the centre moves faster than the sides. It has also been

proved that the surface portions move more rapidly than the deeper

layers and that the motion is slowest at the sides and bottom where

friction is greatest.

The rate of motion past the same spot is not uniform. Heat accelerates

it, cold arrests it, and the pressure of a large amount of water

stimulates the flow. The rate of flow under the same conditions varies

at different parts of the glacier directly as the thickness of ice, the

steepness of slope and the smoothness of rocky floor. Generally

speaking, the rate of motion depends upon the amount of ice that forms

the "head" pressure, the slope of the under surface and of the upper

surface, the nature of the floor, the temperature and the amount of

water present in the ice. The ordinary rate of motion is very slow. In

Switzerland it is from 1 or 2 in. to 4 ft. per day, in Alaska 7 ft., in

Greenland 50 to 60 ft., and occasionally 100 ft. per day in the height

of summer under exceptional conditions of quantity of ice and of water

and slope. Measurements of Swiss glaciers show that near the ice foot

where wastage is great there is very little movement, and observations

upon the inland border of Greenland ice show that it is almost

stationary over long distances. In many aspects the motion of a body of

ice resembles that of a body of water, and an alpine glacier is often

called an ice-river, since like a river it moves faster in the centre

than at the sides and at the top faster than at the bottom. A glacier

follows a curve in the same way as a river, and there appear to be ice

swirls and eddies as well as an upward creep on shelving curves

recalling many features of stream action. The rate of motion of both

ice-stream and river is accelerated by quantity and steepness of slope

and retarded by roughness of bed, but here the comparison ends, for

temperature does not affect the rate of water motion, nor will a liquid

crack into crevasses as a glacier does, or move upwards over an adverse

slope as a glacier always does when there is sufficient "head" of ice

above it. So that although in many respects ice behaves as a viscous

fluid the comparison with such a fluid is not perfect. The cause of

glacier motion must be based upon some more or less complex

considerations. The flakes of snow are gradually transformed into

granules because the points and angles of the original flakes melt and

evaporate more readily than the more solid central portions, which

become aggregated round some master flake that continues to grow in the

neve at the expense of its smaller neighbours, and increases in size

until finally the glacier ice is composed of a mass of interlocked

crystalline granules, some as large as a walnut, closely compacted under

pressure with the principal crystalline axes in various directions. In

the upper portions of the glacier movement due to pressure probably

takes place by the gliding of one granule over another. In this

connexion it must be noted that pressure lowers the melting point of ice

while tension raises it, and at all points of pressure there is

therefore a tendency to momentary melting, and also to some evaporation

due to the heat caused by pressure, and at the intermediate tension

spaces between the points of pressure this resultant liquid and vapour

will be at once re-frozen and become solid. The granular movement is

thus greatly facilitated, while the body of ice remains in a crystalline

solid condition. In this connexion it is well to remember that the

pressure of the glacier upon its floor will have the same result, but

the effect here is a mass-effect and facilitates the gliding of the ice

over obstacles, since the friction produces heat and the pressure lowers

the melting point, so that the two causes tend to liquefy the portion

where pressure is greatest and so to "lubricate" the prominences and

enable the glacier to slide more easily over them, while the liquid thus

produced is re-frozen when the pressure is removed.

In polar regions of very low temperature a very considerable amount of

pressure must be necessary before the ice granules yield to momentary

liquefaction at the points of pressure, and this probably accounts for

the extreme thickness of the Arctic and Antarctic ice-caps where the

slopes are moderate, for although equally low temperatures are found in

high Alpine snow-fields the slopes there are exceedingly steep and

motion is therefore more easily produced.

Observations made upon the Greenland glaciers indicate a considerable

amount of "shearing" movement in the lower portions of a glacier. Where

obstacles in the bed of the glacier arrest the movement of the ice

immediately above it, or where the lower portion of the glacier is

choked by debris, the upper ice glides over the lower in shearing planes

that are sometimes strongly marked by debris caught and pushed forwards

along these planes of foliation. It must be remembered that there is a

solid push from behind upon the lower portion of a glacier, quite

different from the pressure of a body of water upon any point, for the

pressure of a fluid is equal in all directions, and also that this push

will tend to set the crystalline granules in positions in which their

crystalline axes are parallel along the gliding planes. The production

of gliding planes is in some cases facilitated by the descent into the

glacier of water melted during summer, where it expands in freezing and

pushes the adjacent ice away from it, forming a surface along which

movement is readily established.

If under all circumstances the glacier melted under pressure at the

bottom, glacial abrasion would be nearly impossible, since every small

stone and fragment of rock would rotate in a liquid shell as the ice

moved forward, but since the pressure is not always sufficient to

produce melting, the glacier sometimes remains dry at its base; rock

fragments are held firmly; and a dry glacier may thus become a graving

tool of enormous power. Whatever views may be adopted as to the causes

of glacier motion, the peculiar character of glacier ice as distinct

from homogeneous river or pond ice must be kept in view, as well as the

characteristic tendency of water to expand in freezing, the lowering of

the melting point of ice under pressure, the raising of the melting

point under tension, the production of gliding or shearing planes under

pressure from above, the presence in summer of a considerable quantity

of water in the lower portions of the glacier which are thus loosened,

the cracking of ice (as into crevasses), under sudden strain, and the

regelation of ice in contact. A result of this last process is that

fissures are not permanent, but having been produced by the passage of

ice over an obstruction, they subsequently become healed when the ice

proceeds over a flatter bed. Finally it must be remembered that although

glacier ice behaves in some sense like a viscous fluid its condition is

totally different, since "a glacier is a crystalline rock of the purest

and simplest type, and it never has other than the crystalline state."

_Characteristics._--The general appearance of a glacier varies according

to its environment of position and temperature. The upper portion is

hidden by neve and often by freshly fallen snow, and is smooth and

unbroken. During the summer, when little snow falls, the body of the

glacier moves away from the snow-field and a gaping crevasse of great

depth is usually established called the _bergschrund_, which is

sometimes taken as the upper limit of the glacier. The glacier as it

moves down the valley may become "loaded" in various ways. Rock-falls

send periodical showers of stones upon it from the heights, and these

are spread out into long lines at the glacier sides as the ice moves

downwards carrying the rock fragments with it. These are the "lateral

moraines." When two or more glaciers descending adjacent valleys

converge into one glacier one or more sides of the higher valleys

disappear, and the ice that was contained in several valleys is now

carried by one. In the simplest case where two valleys converge into one

the two inner lateral moraines meet and continue to stream down the

larger valley as one "median moraine." Where several valleys meet there

are several such parallel median moraines, and so long as the ice

remains unbroken these will be carried upon the surface of the glacier

and finally tipped over the end. There is, however, differential heating

of rock and ice, and if the stones carried are thin they tend to sink

into the ice because they absorb heat readily and melt the ice under

them. Dust has the same effect and produces "dust wells" that honeycomb

the upper surface of the ice with holes into which the dust sinks. If

the moraine rocks are thick they prevent the ice under them from melting

in sunlight, and isolated blocks often remain supported upon ice-pillars

in the form of ice tables, which finally collapse, so that such rocks

may be scattered out of the line of the moraine. As the glacier descends

into the lower valleys it is more strongly heated, and surface streams

are established in consequence that flow into channels caused by unequal

melting of the ice and finally plunge into crevasses. These crevasses

are formed by strains established as the central parts drag away from

the sides of the glacier and the upper surface from the lower, and more

markedly by the tension due to a sudden bend in the glacier caused by an

inequality in its bed which must be over-ridden. These crevasses are

developed at right angles to the strain and often produce intersecting

fissures in several directions. The morainic material is gradually

dispersed by the inequalities produced, and is further distributed by

the action of superficial streams until the whole surface is strewn with

stones and debris, and presents, as in the lower portions of the Mer de

Glace, an exceedingly dirty appearance. Many blocks of stone fall into

the gaping crevasses and much loose rock is carried down as "englacial

material" in the body of the glacier. Some of it reaches the bottom and

becomes part of the "ground moraine" which underlies the glacier, at

least from the _bergschrund_ to the "snout," where much of it is carried

away by the issuing stream and spread finally on to the plains below. It

appears that a very considerable amount of degradation is caused under

the _bergschrund_ by the mass of ice "plucking" and dragging great

blocks of rock from the side of the mountain valley where the great head

of ice rests in winter and whence it begins to move in summer. These

blocks and many smaller fragments are carried downwards wedged in the

ice and cause powerful abrasion upon the rocky floor, rasping and

scoring the channel, producing conspicuous striae, polishing and

rounding the rock surfaces, and grinding the contained fragments as well

as the surface over which it passes into small fragments and fine

powder, from which "boulder clay" or "till" is finally produced.

Emerging, then, from the snow-field as pure granular ice the glacier

gradually becomes strewn and filled with foreign material, not only from

above but also, as is very evident in some Greenland glaciers,

occasionally from below by masses of fragments that move upwards along

gliding planes, or are forced upwards by slow swirls in the ice itself.

As a glacier is a very brittle body any abrupt change in gradient will

produce a number of crevasses, and these, together with those produced

by dragging strains, will frequently wedge the glacier into a mass of

pinnacles or _seracs_ that may be partially healed but are usually

evident when the melting end of the glacier emerges suddenly from a

steep valley. Here the streams widen the weaker portions and the moraine

rocks fall from the end to produce the "terminal" moraine, which usually

lies in a crescentic heap encircling the glacier snout, whence it can

only be moved by a further advance of the glacier or by the ordinary

slow process of atmospheric denudation.

In cases where no rock falls upon the surface there is a considerable

amount of englacial material due to upturning either over accumulated

ground debris or over structural inequalities in the rock floor. This is

well seen at the steep sides and ends of Greenland glaciers, where

material frequently comes to the surface of the melting ice and produces

median and lateral moraines, besides appearing in enormous "eyes"

surrounded in the glacial body by contorted and foliated ice and

sometimes producing heaps and embankments as it is pushed out at the end

of the melting ice.

The environment of temperature requires consideration. At the upper or

dorsal portion of the glacier there is a zone of variable (winter and

summer) temperature, beneath which, if the ice is thick enough, there is

a zone of constant temperature which will be about the mean annual

temperature of the region of the snow-field. Underlying this there is a

more or less constant ventral or ground temperature, depending mainly

upon the internal heat of the earth, which is conducted to the under

surface of the glacier where it slowly melts the ice, the more readily

because the pressure lowers the melting point considerably, so that

streams of water run constantly from beneath many glaciers, adding their

volume to the springs which issue from the rock. The middle zone of

constant temperature is wedge-shaped in "alpine" glaciers, the apex

pointing downwards to the zone of waste. The upper zone of variable

temperature is thinnest in the snow-field where the mean temperature is

lowest, and entirely dominant in the snout end of the glacier where the

zone of constant temperature disappears. Two temperature wedges are thus

superposed base to point, the one being thickest where the other is

thinnest, and both these lie upon the basal film of temperature where

the escaping earth-heat is strengthened by that due to friction and

pressure. The cold wave of winter may pass right through a thin glacier,

or the constant temperature may be too low to permit of the ice melting

at the base, in which cases the glacier is "dry" and has great eroding

power. But in the lower warmer portions water running through crevasses

will raise the temperature, and increase the strength of the downward

heat wave, while the mean annual temperature being there higher, the

combined result will be that the glacier will gradually become "wet" at

the base and have little eroding power, and it will become more and more

wet as it moves down the lower valley zone of ice-waste, until at last

the balance is reached between waste and supply and the glacier finally

disappears.

If the mean annual temperature be 20 deg. F., and the mean winter

temperature be -12 deg. F., as in parts of Greenland, all the ice must

be considerably below the melting point, since the pressure of ice a

mile in depth lowers the melting point only to 30 deg. F., and the

earth-heat is only sufficient to melt 1/4 in. of ice in a year.

Therefore in these regions, and in snow-fields and high glaciers with an

equal or lower mean temperature than 20 deg. F., the glacier will be

"dry" throughout, which may account for the great eroding power stated

to exist near the _bergschrund_ in glaciers of an alpine type, which

usually have their origin on precipitous slopes.

A considerable amount of ice-waste takes place by water-drainage, though

much is the result of constant evaporation from the ice surface. The

lower end of a glacier is in summer flooded by streams of water that

pour along cracks and plunge into crevasses, often forming "pot-holes"

or _moulins_ where stones are swirled round in a glacial "mill" and wear

holes in the solid rock below. Some of these streams issue in a spout

half way up the glacier's end wall, but the majority find their way

through it and join the water running along the glacier floor and

emerging where the glacier ends in a large glacial stream.

_Results of Glacial Action._--A glacier is a degrading and an aggrading

agent. Much difference of opinion exists as to the potency of a glacier

to alter surface features, some maintaining that it is extraordinarily

effective, and considering that a valley glacier forms a pronounced

_cirque_ at the region of its origin and that the cirque is gradually

cut backward until a long and deep valley is formed (which becomes

evident, as in the Rocky Mountains, in an upper valley with "reversed

grade" when the glacier disappears), and also that the end of a glacier

plunging into a valley or a fjord will gouge a deep basin at its region

of impact. The Alaskan and Norwegian fjords and the rock basins of the

Scottish lochs are adduced as examples. Other writers maintain that a

glacier is only a modifying and not a dominant agent in its effects upon

the land-surface, considering, for example, that a glacier coming down a

lateral valley will preserve the valley from the atmospheric denudation

which has produced the main valley over which the lateral valley

"hangs," a result which the believers in strong glacial action hold to

be due to the more powerful action of the main glacier as contrasted

with the weaker action of that in the lateral valley. Both the advocates

and the opponents of strenuous ice action agree that a V-shaped valley

of stream erosion is converted to a U-shaped valley of glacial

modification, and that rock surfaces are rounded into _roches

moutonnees_, and are grooved and striated by the passage of ice shod

with fragments of rock, while the subglacial material is ground into

finer and finer fragments until it becomes mud and "rock-flour" as the

glacier proceeds. In any case striking results are manifest in any

formerly glaciated region. The high peaks rise into pinnacles, and

ridges with "house-roof" structure, above the former glacier, while

below it the contours are all rounded and typically subdued. A landscape

that was formerly completely covered by a moving ice-cap has none but

these rounded features of dome-shaped hills and U-shaped valleys that at

least bear evidence to the great modifying power that a glacier has upon

a landscape.

There is no conflict of opinion with regard to glacial aggradation and

the distribution of superglacial, englacial and subglacial material,

which during the active existence of a glacier is finally distributed by

glacial streams that produce very considerable alluviation. In many

regions which were covered by the Pleistocene ice-sheet the work of the

glacier was arrested by melting before it was half done. Great deposits

of till and boulder clay that lay beneath the glaciers were abandoned

_in situ_, and remain as an unsorted mixture of large boulders, pebbles

and mingled fragments, embedded in clay or sand. The lateral, median and

terminal moraines were stranded where they sank as the ice disappeared,

and together with perched blocks (_roches perchees_) remain as a

permanent record of former conditions which are now found to have

existed temporarily in much earlier geological times. In glaciated North

America lateral moraines are found that are 500 to 1000 ft. high and in

northern Italy 1500 to 2000 ft. high. The surface of the ground in all

these places is modified into the characteristic glaciated landscape,

and many formerly deep valleys are choked with glacial debris either

completely changing the local drainage systems, or compelling the

reappearing streams to cut new channels in a superposed drainage system.

Kames also and eskers (q.v.) are left under certain conditions, with

many puzzling deposits that are clearly due to some features of ice-work

not thoroughly understood.

See L. Agassiz, _Etudes sur les glaciers_ (Neuchatel, 1840) and

_Nouvelles Etudes ..._ (Paris, 1847); N. S. Shaler and W. M. Davis,

_Glaciers_ (Boston, 1881); A. Penck, _Die Begletscherung der deutschen

Alpen_ (Leipzig, 1882); J. Tyndall, _The Glaciers of the Alps_

(London, 1896); T. G. Bonney, _Ice-Work, Past and Present_ (London,

1896); I. C. Russell, _Glaciers of North America_ (Boston, 1897); E.

Richter, _Neue Ergebnisse und Probleme der Gletscherforschung_

(Vienna, 1899); F. Forel, _Essai sur les variations periodiques des

glaciers_ (Geneva, 1881 and 1900); H. Hess, _Die Gletscher_

(Brunswick, 1904). (E. C. Sp.)

GLACIS, in military engineering (see FORTIFICATION AND SIEGECRAFT), an

artificial slope of earth in the front of works, so constructed as to

keep an assailant under the fire of the defenders to the last possible

moment. On the natural ground-level, troops attacking any high work

would be sheltered from its fire when close up to it; the ground

therefore is raised to form a glacis, which is swept by the fire of the

parapet. More generally, the term is used to denote any slope, natural

or artificial, which fulfils the above requirements.

GLADBACH, the name of two towns in Germany distinguished as

Bergisch-Gladbach and Munchen-Gladbach.

1. BERGISCH-GLADBACH is in Rhenish Prussia, 8 m. N.E. of Cologne by

rail. Pop. (1905) 13,410. It possesses four large paper mills and among

its other industries are paste-board, powder, percussion caps, nets and

machinery. Ironstone, peat and lime are found in the vicinity. The town

has four Roman Catholic churches and one Protestant. The

Stundenthalshohe, a popular resort, is in the neighbourhood, and near

Gladbach is Altenberg, with a remarkably fine church, built for the

Cistercian abbey at this place.

2. MUNCHEN-GLADBACH, also in Rhenish Prussia, 16 m. W.S.W. of Dusseldorf

on the main line of railway to Aix-la-Chapelle. Pop. (1885) 44,230;

(1905) 60,714. It is one of the chief manufacturing places in Rhenish

Prussia, its principal industries being the spinning and weaving of

cotton, the manufacture of silks, velvet, ribbon and damasks, and dyeing

and bleaching. There are also tanneries, tobacco manufactories, machine

works and foundries. The town possesses a fine park and has statues of

the emperor William I. and of Prince Bismarck. There are ten Roman

Catholic churches here, among them being the beautiful minster, with a

Gothic choir dating from 1250, a nave dating from the beginning of the

13th century and a crypt of the 8th century. The town has two hospitals,

several schools, and is the headquarters of important insurance

societies. Gladbach existed before the time of Charlemagne, and a

Benedictine monastery was founded near it in 793. It was thus called

Munchen-Gladbach or Monks' Gladbach, to distinguish it from another town

of the same name. The monastery was suppressed in 1802. It became a town

in 1336; weaving was introduced here towards the end of the 18th

century, and having belonged for a long time to the duchy of Juliers it

came into the possession of Prussia in 1815.

See Strauss, _Geschichte der Stadt Munchen-Gladbach_ (1895); and G.

Eckertz, _Das Verbruderungs und Todtenbuch der Abtei Gladbach_ (1881).

GLADDEN, WASHINGTON (1836- ), American Congregational divine, was born

in Pottsgrove, Pennsylvania, on the 11th of February 1836. He graduated

at Williams College in 1859, preached in churches in Brooklyn,

Morrisania (New York City), North Adams, Massachusetts, and Springfield,

Massachusetts, and in 1882 became pastor of the First Congregational

Church of Columbus, Ohio. He was an editor of the _Independent_ in

1871-1875, and a frequent contributor to it and other periodicals. He

consistently and earnestly urged in pulpit and press the need of

personal, civil and, particularly, social righteousness, and in

1900-1902 was a member of the city council of Columbus. Among his many

publications, which include sermons, occasional addresses, &c., are:

_Plain Thoughts on the Art of Living_ (1868); _Workingmen and their

Employers_ (1876); _The Christian Way_ (1877); _Things New and Old_

(1884); _Applied Christianity_ (1887); _Tools and the Man--Property and

Industry under the Christian Law_ (1893); _The Church and the Kingdom_

(1894), arguing against a confusion and misuse of these two terms;

_Seven Puzzling Bible Books_ (1897); _How much is Left of the Old

Doctrines_ (1899); _Social Salvation_ (1901); _Witnesses of the Light_

(1903); the William Belden Noble Lectures (Harvard), being addresses on

Dante, Michelangelo, Fichte, Hugo, Wagner and Ruskin; _The New Idolatry_

(1905); _Christianity and Socialism_ (1906), and _The Church and Modern

Life_ (1908). In 1909 he published his _Recollections_.

GLADIATORS (from Lat. _gladius_, sword), professional combatants who

fought to the death in Roman public shows. 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; and we learn from Isidore

of Seville (_Origines_, x.) that the name for a trainer of gladiators

(_lanista_) is an Etruscan word meaning butcher or executioner. These

gladiatorial games are evidently a survival of the practice of

immolating slaves and prisoners on the tombs of illustrious chieftains,

a practice recorded in Greek, Roman and Scandinavian legends, and

traceable even as late as the 19th century as the Indian _suttee_. Even

at Rome they were for a long time confined to funerals, and hence the

older name for gladiators was _bustuarii_; 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 and the

circus.

The first gladiators are said, on the authority of Valerius Maximus (ii.

4. 7), to have been exhibited at Rome in the Forum Boarium in 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 Titus

Flamininus celebrated his father's obsequies by a three-days' fight, in

which 74 gladiators took part. Julius Caesar engaged such extravagant

numbers for his aedileship that his political opponents took fright and

carried a decree of the senate imposing a certain limit of numbers, but

notwithstanding this restriction he was able to exhibit no less than 300

pairs. 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

bodyguard, 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 praetor to exhibit more than 120 gladiators, yet allusions in

Horace (_Sat._ ii. 3. 85) and Persius (vi. 48) 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 Juvenal (viii. 199) has handed down to eternal infamy

the descendant of the Gracchi who appeared without disguise as a

_retiarius_, and begged his life from the _secutor_, who blushed to

conquer one so noble and so vile.[1] 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 at the Saturnalia of A.D. 90 arranged a battle

between dwarfs and women. Even women of high birth fought in the arena,

and it was not till A.D. 200 that the practice was forbidden by edict.

How widely the taste for these sanguinary spectacles extended throughout

the Roman provinces is attested by monuments, inscriptions 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. After

Italy, Gaul, North Africa and Spain were most famous for their

amphitheatres; and Greece was the only Roman province where the

institution never thoroughly took root.

Gladiators were commonly drawn either from prisoners of war, or slaves

or criminals condemned to death. Thus in the first class we read of

tattooed Britons in their war chariots, Thracians with their peculiar

bucklers and scimitars, Moors from the villages round Atlas and negroes

from central Africa, exhibited in the Colosseum. Down to the time of the

empire only greater malefactors, such as brigands and incendiaries, were

condemned to the arena; but by Caligula, Claudius and Nero this

punishment was extended to minor offences, such as fraud and peculation,

in order to supply the growing demand for victims. For the first century

of the empire it was lawful for masters to sell their slaves as

gladiators, but this was forbidden by Hadrian and Marcus Aurelius.

Besides these three regular classes, the ranks were recruited by a

considerable number of freedmen and Roman citizens who had squandered

their estates and voluntarily took the _auctoramentum gladiatorium_, by

which for a stated time they bound themselves to the _lanista_. Even men

of birth and fortune not seldom entered the lists, either for the pure

love of fighting or to gratify the whim of some dissolute emperor; and

one emperor, Commodus, actually appeared in person in the arena.

Gladiators were trained in schools (_ludi_) owned either by the state or

by private citizens, and though the trade of a _lanista_ was considered

disgraceful, to own gladiators and let them out for hire was reckoned a

legitimate branch of commerce. Thus Cicero, in his letters to Atticus,

congratulates his friend on the good bargain he had made in purchasing a

band, and urges that he might easily recoup himself by consenting to let

them out twice. Men recruited mainly from slaves and criminals, whose

lives hung on a thread, must have been more dangerous characters than

modern galley slaves or convicts; and, though highly fed and carefully

tended, they were of necessity subject to an iron discipline. In the

school of gladiators discovered at Pompeii, of the sixty-three skeletons

buried in the cells many were in irons. But hard as was the gladiators'

lot,--so hard that special precautions had to be taken to prevent

suicide,--it had its consolations. A successful gladiator enjoyed far

greater fame than any modern prize-fighter or athlete. He was presented

with broad pieces, chains and jewelled helmets, such as may be seen in

the museum at Naples; poets like Martial sang his prowess; his portrait

was multiplied on vases, lamps and gems; and high-born ladies contended

for his favours. Mixed, too, with the lowest dregs of the city, there

must have been many noble barbarians condemned to the vile trade by the

hard fate of war. There are few finer characters in Roman history than

the Thracian Spartacus, who, escaping with seventy of his comrades from

the school of Lentulus at Capua, for three years defied the legions of

Rome; and after Antony's defeat at Actium, the only part of his army

that remained faithful to his cause were the gladiators whom he had

enrolled at Cyzicus to grace his anticipated victory.

There were various classes of gladiators, distinguished by their arms or

modes of fighting. The Samnites fought with the national weapons--a

large oblong shield, a vizor, a plumed helmet and a short sword. The

Thraces had a small round buckler and a dagger curved like a scythe;

they were generally pitted against the Mirmillones, who were armed in

Gallic fashion with helmet, sword and shield, and were so called from

the fish ([Greek: mormulos] or [Greek: mormuros]) which served as the

crest of their helmet. In like manner the Retiarius was matched with the

Secutor: the former had nothing on but a short tunic or apron, and

sought to entangle his pursuer, who was fully armed, with the cast-net

(_jaculum_) that he carried in his right hand; and if successful, he

despatched him with the trident (_tridens_, _fuscina_) that he carried

in his left. We may also mention the Andabatae who are generally

believed to have fought on horseback and wore helmets with closed

vizors; the Dimachaeri of the later empire, who carried a short sword in

each hand; the Essedarii, who fought from chariots like the ancient

Britons; the Hoplomachi, who wore a complete suit of armour; and the

Laquearii, who tried to lasso their antagonists.

Gladiators also received special names according to the time or

circumstances in which they exercised their calling. The Bustuarii have

already been mentioned; the Catervarii fought, not in pairs, but in

bands; the Meridiani came forward in the middle of the day for the

entertainment of those spectators who had not left their seats; the

Ordinarii fought only in pairs, in the regular way; the Fiscales were

trained and supported at the expense of the imperial treasury; the

Paegniarii used harmless weapons, and their exhibition was a sham one;

the Postulaticii were those whose appearance was asked as a favour from

the giver of the show, in addition to those already exhibited.

The shows were announced some days before they took place by bills

affixed to the walls of houses and public buildings, copies of which

were also sold in the streets. These bills gave the names of the chief

pairs of competitors, the date of the show, the name of the giver and

the different kinds of combats. The spectacle began with a procession of

the gladiators through the arena, after which their swords were examined

by the giver of the show. The proceedings opened with a sham fight

(_praelusio_, _prolusio_) with wooden swords and javelins. The signal

for real fighting was given by the sound of the trumpet, those who

showed fear being driven on to the arena with whips and red-hot irons.

When a gladiator was wounded, the spectators shouted _Habet_ (he is

wounded); if he was at the mercy of his adversary, he lifted up his

forefinger to implore the clemency of the people, with whom (in the

later times of the republic) the giver left the decision as to his life

or death. If the spectators were in favour of mercy, they waved their

handkerchiefs; if they desired the death of the conquered gladiator,

they turned their thumbs downwards.[2] The reward of victory consisted

of branches of palm, sometimes of money. Gladiators who had exercised

their calling for a long time, or such as displayed special skill and

bravery, were presented with a wooden sword (_rudis_), and discharged

from further service.

Both the estimation in which gladiatorial games were held by Roman

moralists, and the influence that they exercised upon the morals and

genius of the nation, deserve notice. The Roman was essentially cruel,

not so much from spite or vindictiveness as from callousness and

defective sympathies. This element of inhumanity and brutality must

have been deeply ingrained in the national character to have allowed

the games to become popular, but there can be no doubt that it was fed

and fostered by the savage form which their amusements took. That the

sight of bloodshed provokes a love of bloodshed and cruelty is a

commonplace of morals. To the horrors of the arena we may attribute in

part, not only the brutal treatment of their slaves and prisoners, but

the frequency of suicide among the Romans. On the other hand, we

should be careful not to exaggerate the effects or draw too sweeping

inferences from the prevalence of this degrading amusement. Human

nature is happily illogical; and we know that many of the Roman

statesmen who gave these games, and themselves enjoyed these sights of

blood, were in every other department of life

irreproachable--indulgent fathers, humane generals and mild rulers of

provinces. In the present state of society it is difficult to conceive

how a man of taste can have endured to gaze upon a scene of human

butchery. Yet we should remember that it is not so long since

bear-baiting was prohibited in England, and we are only now attaining

that stage of morality in respect of cruelty to animals that was

reached in the 5th century, by the help of Christianity, in respect of

cruelty to men. We shall not then be greatly surprised if hardly one

of the Roman moralists is found to raise his voice against this

amusement, except on the score of extravagance. Cicero in a well-known

passage commends the gladiatorial games as the best discipline against

the fear of death and suffering that can be presented to the eye. The

younger Pliny, who perhaps of all Romans approaches nearest to our

ideal of a cultured gentleman, speaks approvingly of them. Marcus

Aurelius, though he did much to mitigate their horrors, yet in his

writings condemns the monotony rather than the cruelty. Seneca is

indeed a splendid exception, and his letter to Lentulus is an eloquent

protest against this inhuman sport. But it is without a parallel till

we come to the writings of the Christian fathers, Tertullian,

Lactantius, Cyprian and Augustine. In the _Confessions_ of the last

there occurs a narrative which is worth quoting as a proof of the

strange fascination which the games exercised even on a religious man

and a Christian. He tells us how his friend Alipius was dragged

against his will to the amphitheatre, how he strove to quiet his

conscience by closing his eyes, how at some exciting crisis the shouts

of the whole assembly aroused his curiosity, how he looked and was

lost, grew drunk with the sight of blood, and returned again and

again, knowing his guilt yet unable to abstain. The first Christian

emperor was persuaded to issue an edict abolishing gladiatorial games

(325), yet in 404 we read of an exhibition of gladiators to celebrate

the triumph of Honorius over the Goths, and it is said that they were

not totally extinct in the West till the time of Theodoric.

Gladiators formed admirable models for the sculptor. One of the finest

pieces of ancient sculpture that has come down to us is the "Wounded

Gladiator" of the National Museum at Naples. The so-called "Fighting

Gladiator" of the Borghese collection, now in the Museum of the

Louvre, and the "Dying Gladiator" of the Capitoline Museum, which

inspired the famous stanza of _Childe Harold_, have been pronounced by

modern antiquaries to represent, not gladiators, but warriors. In this

connexion we may mention the admirable picture of Gerome which bears

the title, "Ave, Caesar, morituri te salutant."

The attention of archaeologists has been recently directed to the

tesserae of gladiators. These tesserae, of which about sixty exist in

various museums, are small oblong tablets of ivory or bone, with an

inscription on each of the four sides. The first line contains a name

in the nominative case, presumably that of the gladiator; the second

line a name in the genitive, that of the _patronus_ or _dominus_; the

third line begins with the letters SP (for _spectatus_ = approved),

which shows that the gladiator had passed his preliminary trials; this

is followed by a day of a Roman month; and in the fourth line are the

names of the consuls of a particular year.

AUTHORITIES.--All needful information on the subject will be found in

L. Friedlander's _Darstellungen aus der Sittengeschichte Roms_, (part

ii, 6th ed., 1889), and in the section by him on "The Games" in

Marquardt's _Romische Staatsverwaltung_, iii. (1885) p. 554; see also

article by G. Lafaye in Daremberg and Saglio, _Dictionnaire des

antiquites_. See also F. W. Ritschl, _Tesserae gladiatoriae_ (1864)

and P. J. Meier, _De gladiatura Romana quaestiones selectae_ (1881).

The articles by Lipsius on the _Saturnalia_ and _amphitheatrum_ in

Graevius, _Thesaurus antiquitatum Romanarum_, ix., may still be

consulted with advantage.