CELTES, KONRAD CENTO (town of Italy)
CELTIBERIA CENTO (composition)
CEMENT CENTRAL AMERICA
CEMETERY CENTRAL FALLS
CENCI, BEATRICE CENTRALIA
CENOBITES CENTRAL INDIA
CENOMANI CENTRAL PROVINCES AND BERAR
CENOTAPH CENTUMVIRI
CENSOR CENTURION
CENSORINUS CENTURIPE
CENSUS CENTURY
CENTAUREA CEOS
CENTAURS CEPHALIC INDEX
CENTAURUS CEPHALONIA
CENTAURY CEPHALOPODA
CENTENARY CEPHEUS
CENTERVILLE CEPHISODOTUS
CENTIPEDE CERAM
CENTLIVRE, SUSANNA CERAMICS
CELTES, KONRAD (1459-1508), German humanist and Latin poet, the son of a
vintner named Pickel (of which Celtes is the Greek translation), was
born at Wipfeld near Schweinfurt. He early ran away from home to avoid
being set to his father's trade, and at Heidelberg was lucky enough to
find a generous patron in Johann von Dalberg and a teacher in Agricola.
After the death of the latter (1485) Celtes led the wandering life of a
scholar of the Renaissance, visiting most of the countries of the
continent, teaching in various universities, and everywhere establishing
learned societies on the model of the academy of Pomponius Laetus at
Rome. Among these was the _Sodalitas litteraria Rhenana_ or _Celtica_ at
Mainz (1491). In 1486 he published his first book, _Ars versificandi et
carminum_, which created an immense sensation and gained him the honour
of being crowned as the first poet laureate of Germany, the ceremony
being performed by the emperor Frederick III. at the diet of Nuremberg
in 1487. In 1497 he was appointed by the emperor Maximilian I. professor
of poetry and rhetoric at Vienna, and in 1502 was made head of the new
Collegium Poetarum et Mathematicorum, with the right of conferring the
laureateship. He did much to introduce system into the methods of
teaching, to purify the Latin of learned intercourse, and to further the
study of the classics, especially the Greek. But he was more than a mere
classicist of the Renaissance. He was keenly interested in history and
topography, especially in that of his native country. It was he who
first unearthed (in the convent of St Emmeran at Regensburg) the
remarkable Latin poems of the nun Hrosvitha of Gandersheim, of which he
published an edition (Nuremberg, 1501), the historical poem _Ligurinus
sive de rebus gestis Frederici primi imperatoris libri x._ (Augsburg,
1507), and the celebrated map of the Roman empire known as the _Tabula
Peutingeriana_ (after Konrad Peutinger, to whom he left it). He
projected a great work on Germany; but of this only the _Germania
generalis_ and an historical work in prose, _De origine, situ, moribus
et institutis Nurimbergae libettus_, saw the light. As a writer of Latin
verse Celtes far surpassed any of his predecessors. He composed odes,
elegies, epigrams, dramatic pieces and an unfinished epic, the
_Theodoriceis_. His epigrams, edited by Hartfelder, were published at
Berlin in 1881. His editions of the classics are now, of course, out of
date. He died at Vienna on the 4th of February 1508.
For a full list of Celtes's works see Engelbert Klüpfel, _De vita et
scriptis Conradi Celtis_ (2 vols., Freiburg, 1827); also Johann
Aschbach, _Die früheren Wanderjahre des Conrad Celtes_ (Vienna, 1869);
Hartmann, _Konrad Celtes in Nürnberg _(Nuremberg, 1889).
CELTIBERIA, a term used by Greek and Roman writers to denote, sometimes
the whole north-east of Spain, and sometimes the north-east part of the
central plateau of the peninsula. The latter was probably the correct
use. The Celtiberi, in this narrower sense, were not so much one tribe
as a group of cantons--Arevaci, Pelendones, Berones and four or five
others. They were the most warlike people in Spain, and for a long time
offered a stubborn resistance to the Romans. Originally Carthaginian
mercenaries, they were induced to serve the Romans in a similar
capacity, and Livy (xxiv. 49) distinctly states that they were the first
mercenaries in the Roman army. They did not, however, keep faith, and
several campaigns were undertaken against them. In 179 B.C. the whole
country was subdued by T. Sempronius Gracchus, who by his generous
treatment of the vanquished gained their esteem and affection. In 153
they again revolted, and were not finally overcome until the capture of
Numantia (133). The twenty years' war waged round this city, and its
siege and destruction by Scipio the Younger (133 B.C.) form only the
most famous episode in the long struggle, which has left its mark in
entrenchments near Numantia excavated in 1906-1907 by German
archaeologists. After the fall of Numantia, and still more after the
death of Sertorius (72 B.C.), the Celtiberians became gradually
romanized, and town life grew up among their valleys; Clunia, for
instance, became a Roman municipality, and ruins of its walls, gates and
theatre testify to its civilization; while Bilbilis (Bambola), another
municipality, was the birthplace of the eminently Roman poet Martial.
The Celtiberians may have been so called because they were thought to
be the descendants of Celtic immigrants from Gaul into Iberia (Spain),
or because they were regarded (cf. Lucan iv. 9) as a mixed race of Celts
and Spaniards (Iberians); in either case the name represents a
geographer's theory rather than an ascertained fact. That a strong
Celtic element existed in Spain is proved both by numerous traditions
and by the more trustworthy evidence of place-names. The Celtic
place-names of Spain, however, are not confined to Celtiberia or even to
the north and east; they occur even in the south and west.
A long description of the manners and customs of the Celtiberi is
given by Diodorus Siculus (v. 33, 34). Their country was rough and
unfruitful as a whole (barley, however, was cultivated), being chiefly
used for the pasture of sheep. Its inhabitants either led a nomadic
life or occupied small villages; large towns were few. Their infantry
and cavalry were both excellent. In battle, they adopted the
wedge-shaped formation of the column. They carried double-edged swords
and short daggers for use hand to hand, the steel of which was
hardened by being buried underground; their defensive armour was a
light Gallic shield or a round wicker buckler, and greaves of felt
round their legs. They wore brazen helmets with purple crests, and
rough-haired black cloaks, in which they slept on the bare ground.
Like the Cantabri, they washed themselves with urine instead of water.
They were said to offer sacrifice to a nameless god (Strabo iii. p.
164) at the time of the full moon when all the household danced
together before the doors of the houses. Although cruel to their
enemies, they were hospitable to strangers. They ate meat of all
kinds, and drank a kind of mead. E. Hübner's article in
Pauly-Wissowa's _Realencyclopadie_, iii. (1886-1893), collects all the
ancient references, which are almost all brief. Strabo's notice (bk.
iii.), based perhaps on Poseidonius, is fullest. (F. J. H.)
CEMENT (from Lat. _caementum_, rough pieces of stone, a shortened form
of _caedimentum_, from _caedere_, to cut), apparently first used of a
mixture of broken stone, tiles, &c., with some binding material, and
hence of any material capable of adhering to, and uniting into a
coherent mass, fragments of a substance not in itself adhesive. The term
is often applied to adhesive mixtures employed to unite objects or parts
of objects (see below), but in engineering, when used without
qualification, it means Portland cement, its modifications and
congeners; these are all hydraulic cements, i.e. when set they resist
the action of water, and can, under favourable conditions, be allowed to
set under water.
_Hydraulic Cements_.--It was well known to builders in the earliest
historic times that certain limes would, when set, resist the action of
water, i.e. were hydraulic; it was also known that this property could
be conferred on ordinary lime by admixture of silicious materials such
as pozzuolana or tufa. We have here the two classes into which hydraulic
cements are divided.
Pozzuolanic cement.
When pure chalk or limestone is "burned," i.e. heated in a kiln until
its carbonic acid has been driven off, it yields pure lime. This slakes
violently with water, giving slaked lime, which can be made into a
smooth paste with water and mixed with sand to form common mortar. The
setting of the mortar is due to the drying of the lime (a purely
physical phenomenon, no chemical action occurring between the lime and
the sand). The function of the sand is simply that of a diluent to
prevent undue shrinkage and cracking in drying. Subsequent hardening of
the mortar is caused by the gradual absorption of carbonic acid from the
air by the lime, a skin of carbonate of lime being formed; but the
action is superficial. Mortar made from pure or "fat" lime cannot
withstand the action of water, and is only used for work done above
water-level. If, however, such "fat" lime is mixed in the presence of
water, not with sand but with silica in an active form, i.e. amorphous
and (generally) hydrated, or with a silicate containing silica in an
active condition, it will unite with the silica and form a silicate of
lime capable of resisting the action of water. The mixture of the lime
and active silica or silicate is a pozzuolanic cement. The simplest of
all pozzuolanic cements would be a mixture of pure lime and hydrated
silica, but though the latter is prepared artificially for various
purposes, it is too expensive to be used as a cement material. A similar
obstacle lies in the way of using a certain native form of active
silica, viz. kieselguhr, for it is too valuable as an absorbent of
nitroglycerine, for the manufacture of dynamite, to be available for
making pozzuolanic cement. There are, however, many silicious
substances occurring abundantly in nature which can thus be used. They
are mostly of volcanic origin, and include pumice, tufa, santorin earth,
trass and pozzuolana itself. The following analyses show their general
composition:--
+-----------------------------+-----------+-----------+-----------+
| |Neapolitan | Roman | |
| | Pozzuo- | Pozzuo- | Trass |
| | lana | lana |(per cent) |
| |(per cent) |(per cent) | |
+-----------------------------+-----------+-----------+-----------|
| Soluble silica (SiO2) | 27.80 | 32.64 | 19.32 |
| Insoluble silicious residue | 35.38 | 25.94 | 50.40 |
| Alumina (Al2O3) | / 19.80 | / 22.74 | 13.86 |
| Ferric oxide (Fe2O3) | \ | \ | 3.10 |
| Lime (CaO) | 5.68 | 4.06 | · · |
| Magnesia (MgO) | 0.35 | 1.37 | 0.13 |
| Sulphuric anhydride (SO3) | Trace | Trace | · · |
| Combined water (H2O) | / 4.27 | / 8.92 | 7.57 |
| Carbonic anhydride (CO2) | \ | \ | · · |
| Moisture | · · | · · | 5.04 |
| Alkalis and loss | 6.72 | 4.33 | 0.58 |
| +-----------+-----------+-----------+
| | 100.00 | 100.00 | 100.0 |
+-----------------------------+-----------+-----------+-----------+
An artificial product which serves perfectly as a pozzuolana is
granulated blast-furnace slag. The slag, which must contain a high
percentage of lime, is granulated by being run while fused into
abundance of water. This granulated slag differs from the same slag
allowed to cool slowly, in that a portion of the energy which it
possesses while fused is retained after it has solidified. It bears to
ordinary slowly-cooled slag a similar relation to that borne by plastic
sulphur to ordinary crystalline sulphur. This potential energy becomes
kinetic when the slag is brought into contact with lime in the presence
of water, and causes the formation of a true hydraulic silicate of lime.
The following analysis shows the composition of a typical slag:--
Per Cent.
Insoluble residue 1.04
Silica (SiO2) 31.50
Alumina (Al2O3) 18.56
Manganous oxide (MnO) 0.44
Lime (CaO) 42.22
Magnesia (MgO) 3.18
Soda (Na2O) 0.70
Sulphuric anhydride (SO3) 0.45
Sulphur (S) 2.21
------
100.30
Deduct oxygen equivalent to sulphur 1.10
------
99.20
Granulated slag of this character is ground with slaked lime until both
materials are in a state of fine division and intimately mixed. The
usual proportions are three of slag to one of slaked lime by weight. The
product termed slag cement sets slowly, but ultimately attains a
strength scarcely inferior to that of Portland cement. Although it is
cheap and suitable for many purposes, its use is not large and tends to
decrease. Pozzuolanic cements are little used in England. Generally
speaking, they are only of local importance, their cheapness depending
largely on the nearness and abundance of some suitable volcanic deposit
of the trass or tufa class. They are not usually manufactured by the
careful grinding together of the pozzuolana and the lime, but are mixed
roughly, a great excess of pozzuolana being employed. This excess does
no harm, for that part which fails to unite with the lime serves as a
diluent, much as does sand in mortar. In fact, ordinary pozzuolanic
cement made on the spot where it is to be used may be regarded as a
better kind of common mortar having hydraulic qualities. Good hydraulic
mortars may be made from lime mixed with furnace ashes or burnt clay as
the pozzuolanic constituent.