the death of Sertorius (72 B.C.) that they began to adopt the Roman language, dress, and manners. The chief cities were Legobriga, the capital; Bilbilis, the birthplace of Martial; and Numantia, destroyed by Scipio Africanus after a desperate ten years' resistance, 133 B.C.

CELTS

lacing band might be replaced by an elongated animal form with its feet, its tail, and its top-knot drawn out to interlace with each other, and with the corresponding parts of other lacertine forms, the whole forming a diaper of quaintly expressed and complicated construction. The fretwork was Celtic Ornament, a peculiar development of also elaborated with much ingenuity into most the system of iron-age decoration prevalent in the complicated patterns, a special feature of the style British Isles. Its history is divided into two being its partiality for diagonal frets and patterns periods by the introduction of Christianity, which produced by combinations of oblique lines, in direct engrafted on the older style a number of new elecontrast to the fretwork of Greek and Roman art, ments of decoration brought into the country with which was essentially rectangular. The elliptical the manuscripts of the gospels and psalters, and curves and divergent spirals of the older style, supplied new forms for the display of these ele- which had received their only expression in the ments, such as churches and crosses, shrines, bells, solid forms proper to metal-work, were found to be and crosiers. In its pre-Christian stages, ranging equally capable of adaptation to the purposes of approximately from two or three centuries before the illuminator, and by a similar process of comthe Christian era to about the end of the 6th bination and elaboration they also produced century A.D., it appears principally in connection patterns and diapers of inexhaustible variety and with the metal mountings of harness and horse- beauty. A special feature of Celtic decoration trappings, and on shields, sword-sheaths, mirrors, was its tendency to divide the surface to be armlets, and other articles of personal use and decorated into a series of panels, each of which ornament. The material is usually bronze, but was treated as a separate whole. The finest occasionally silver or gold. The principal charac- examples of Celtic ornament are unquestionably teristics of the pre-Christian style are its preto be found in the grandly illuminated pages of ference for elliptical curves and divergent spirals; manuscript copies of the Gospels, from the 7th its use of chased or engraved lines or dots as a to the 9th century. Of these the most famous for diaper in the spaces of the general design in the elaborate nature of their ornament and the contrast with other spaces left plain; its use of beauty of their colouring are the Book of Kells repoussé work, sometimes in very high relief, at in Trinity College, Dublin, and the Lindisfarne other times in low relief on thin plates riveted Gospels in the British Museum. Of enamelled on in their places in the general design; the metal-work in this period there may be mentioned production of peculiar patterns often in excess- the Ardagh Chalice, perhaps the most elaborate ively high relief in the casting; and the employ- and beautiful of all the products of Celtic art, the ment of champ-levé enamels of red, yellow, blue, Lismore Crosier, and the Monymusk Shrine. Exand green, and settings of coloured vitreous pastes. amples of filigree-work, and chasing or engraving One of the finest examples of such settings occurs in gold and silver of the highest excellence are in the decoration of an oval shield of bronze, from found in the Tara Brooch, the Ardagh Brooches, the bed of the Thames, ornamented with Celtic the Rogart Brooches, and the Hunterston Brooch, patterns in relief, enriched by twenty-seven setthe Shrine of St Patrick's Bell, the Shrine of tings of red enamel, kept in their places by small St Manchan, and the Cross of Cong. The approxcruciform ornaments of bronze riveted in the centre imate dates of the metal-work of the highest excelof each. There are to be seen in the National lence range from the 10th to the 12th century. Museums of London, Edinburgh, and Dublin For sculpture in stone it is only necessary to refer enamelled shields, sword-sheaths, and ornaments generally to the incised slabs and sculptured crosses of horse-trappings in bronze, of great beauty of Scotland and Ireland, ranging from the 9th to and excellence both of design and workmanship, the 12th centuries, the special characteristics of and other articles in bronze, silver, or gold, ornatheir decoration being the same as those of the mented in repoussé work or in relief, with or manuscripts and metal-work already mentioned. without enamel as an enrichment, found in many For illustrations, see BROOCH, CROSS, SCULPparts of England, Scotland, and Ireland, in pagan TURED STONES. See further Kemble's Hora grave-mounds, in crannogs or lake-dwellings, in Ferales, edited by Latham and Franks (1863); earth-houses, in the beds of lakes and rivers, or in Anderson's Scotland in Early Christian and casual deposits under the soil for concealment. In Pagan Times (1881-83); Westwood's Palaoa work entitled Hora Ferales, Mr Franks of the graphia Sacra Pictoria (1845), and Fac-similes of British Museum has figured in colours many of the the Miniatures and Ornaments of Anglo-Saxon and best of these remarkable products of the earliest Irish Manuscripts (1868); O'Neill's Fine Arts known process of champ-levé enamelling, and ad- of Ancient Ireland (1863), and Sculptured Crosses duced evidence to show that it and this peculiar of Ancient Ireland (1857); Stuart's Sculptured style of Celtic ornament which accompanies it Stones of Scotland (Spalding Club, 1856 and 1867); were of indigenous origin, and at this early and Miss Stokes's Early Christian Art in Ireland period peculiar to the British Isles. The re(1887). markable development of Celtic ornament which succeeded the introduction of Christianity was characterised by the association of interlaced work and fretwork with the elliptical curves and divergent spirals which up to that time had been the principal elements of Celtic design. To these were occasionally added a step-like pattern, and diapers of the Z and I shaped patterns sometimes seen in Chinese decoration. The interlaced work was elaborated with excessive care into patterns, presenting an infinite variety of combinations pleasing to the eye, and capable of being harmoniously treated in colours. It was times a simple ribbon-like band, which might be plain, or divided in the middle, or divided into three by lines close to the margin; or the inter

some

Celtis. See NETTLE-TREE.

Celts. The Celtic nations of antiquity had no comprehensive name. Those of the Continent were called Galli by the Romans, and less usually Celta. The Greek equivalents for these terms were Galatai or Galatæ, and Keltoi or Celti. But neither Greeks nor Romans regarded the British Isles as belonging to the Celtic world. They were situated outside it, and lay over against it in the sea; still it was known to men like Julius Cæsar that certain portions of Britain were inhabited by Celts in the sense of Galli or Belgæ.

Celtic ethnology involves many difficult questions, and we shall speak of them in this article mostly according to the more palpable distinctions of speech;

I

CELTS

and in order to proceed as much as possible from the
known to the unknown, we begin by classifying
their idioms. These, whether dead or still spoken,
belong to the Aryan or Indo-European family of
languages, and those of them spoken in modern times
divide themselves into two groups-viz. Goidelic
and Brythonic. (1) The Goidelic group embraces
the dialects termed Gaelic, that is to say, Irish
Gaelic, or Irish as it is now more frequently and
briefly called; Manx Gaelic, or the Gaelic dialect
not yet extinct in the Isle of Man; and Scotch
Gaelic, or the Gaelic spoken in the Highlands and
Islands of Scotland. In ordinary Scotch and English
parlance this is what is understood by the word
Gaelic when it is used without any qualification.
In order to resist one of the delusions to which
charlatans are always leading the unwary, it is
right to say that the words Gael and Gaelic have
nothing to do with Galli. Gael is the simplified
English spelling of a word which is now written
in Scotch and Irish Gaelic Gaidheal, with an
evanescent dh; but the most ancient form known
of it was Goidel, whence the adjective Goidelic,
which has been resorted to by Celtic scholars as
applicable equally to all three Gaelic subdivisions
of the Celtic group here in question. The Celtic
languages of this group are sometimes also called
Erse, which is a term derived from the Scotch form
of the adjective Irish; this was Ersch or Yrisch,
the longer and shorter forms of which appear,
without any distinction, by Kennedy in his answer
to the poet Dunbar, when the latter had called
Kennedy an Ersch brybour baird' and an Ersch
katherane,' in reference to his alleged extrac-
tion from the Irish Scots of Galloway and Carrick.
Kennedy's reply contains the following line (see
Murray's Dialect of the Southern Counties of Scot-
land, 1873, pp. 43-44):

Thou luvis nane Erische, elf, I undirstand,
and he goes on to add

Thy fore fader maid Ersche and Erschmen thin.

used

(2) The Brythonic group embraces the following languages: Welsh, Breton, and Cornish, which has been extinct now for about a century. Two of these belong to Great Britain, and one, the Breton or Armoric, to Little Britain on the other side of the English Channel. These three might be collectively termed British or Britannic, but that both these adjectives have connotations which would be misleading, as they tend to confusion; so here, also, a neutral form, Brythonic, is used, which is derived from Brython, one of the Welsh words for the Welsh and the so-called Ancient Britons, whence their language is sometimes called Brythoneg in Welsh. This last was in Cornish Brethonec, and in Breton Brézonek, meaning respectively the Celtic of Cornwall and of Brittany. Brython or Britto was the national name of all peoples of this branch, just as Goidel or Gael may be treated as the national name of the other branch.

57

test of some of the most palpable differences that
are known to exist between the Goidelic and the
Brythonic idioms to the remains of the Gaulish
language, we find at once that it is to be ranked
with the Brythonic dialects, and not with the
Goidelic ones, and our Brythonic group becomes
what may be more exactly described as a Gallo-
Brythonic one. This further suggests the question
whether there was no continental Celtic idiom
which partook of the characteristics of the Goidelic
branch. The probability is that there was; for
one finds Sulpicius Severus, an ecclesiastical writer
of the 4th century, distinguishing between Celtic
and Gallic or Gaulish, as if both were spoken in his
time. (See Dialogue i. 26, in Migne's Patr. Lat.
vol. xx. col. 201: Tu vero, inquit Postumianus,
vel Celtice, aut, si mavis, Gallice loquere, dum-
modo jam Martinum loquaris.') And the use
of the two names Celta and Galli would seem
to point to the same inference-viz. the exist-
ence in Gaul of two Celtic peoples, the one,
probably, superimposed on the other, as on a van-
quished population, or driving it towards the
south and west. Thus, if the Celtic language
which Sulpicius Severus distinguished from Gaulish
should be ranked with the Goidelic dialects, we
should have alongside of a Gallo-Brythonic group
another which might be called Celto-Brythonic
were it not inconvenient to use the words Celt and
Celtic in two senses. For while the modern usage
applies them indifferently to the whole family,
Sulpicius indicates a narrower sense; and so, in
fact, had Cæsar done centuries before, when he
wrote that one of the three peoples of Gaul was
called Celtæ in their own tongue. He states that
these Celtæ proper, so to say, were separated by
the Garonne from the Aquitani, and by the Seine
and the Marne from the Belga. In other words,
their country extended from the Garonne to the
Seine and Marne, and other Roman writers give it
the name of Celtica; and Dionysius of Halicar-
nassus had heard of a river Celtus, from which
Celtica was supposed to derive its name.
this narrower Celtica, in the sense which Roman
writers gave it, one might form the adjective
Celtican, to apply to its people, in order to avoid
the confusion which must arise from calling them
Celts, whilst using that word also of the whole
family.

From

In order to show the philological reasons for this classification, it would be necessary to go into a variety of details; but let one of these suffice for the present. The Gallo-Brythonic dialects used p where the others would have qu. Take, for example, the early inscriptional Irish for the genitive of the word for 'son'; it was maqvi, corresponding to a nominative which appears as macc or mac in the oldest manuscript Irish; and mac is still the word for 'boy' or 'son' in all the Goidelic dialects. Now the early Brythonic form of this genitive would have been mapi, while in the oldest manuscript Welsh we have map, and in later Welsh máb, 'boy' or 'son.' From this word was formed All this applies only to the neo-Celtic nations, or another, mabon, a boy' or 'youth;' and this in its those among whom Celtic languages are or have old form appears in Latin inscriptions as maponus been in use in modern times, and a question of in Roman inscriptions found in Britain in honour much greater difficulty presents itself when one of the Celtic god Apollo Maponus, so called in attempts to classify likewise the continental Celts reference to his youthfulness. Now from Gaul of ancient history. The reason for this is chiefly we have such names as Eporedorix, Parisii, Petrothe fact that the linguistic data become more pre-corii, and many others, with the consonant p; but carious as one goes back. Thus, for example, the every now and then we have also names with language of the ruling people of ancient Gaul has qu, such as Sequana and Aquitani, together with been left us only in a very few inscriptions, so several instances from Spain, where a people of the that our knowledge of it from that source has to same Celtic branch as those of Celtica had also be complemented by the study of Gaulish proper probably established themselves. names, of which a considerable number is extant in Latin inscriptions and in the writings of Roman and Greek authors. Now, when we apply the

So far, then, as one can get philological data to reason upon, it would seem that the west of Europe had in early times been subjected to two Celtic

Г

г.

1

CEMENTS

cements are slow-setting, and these do not contain
more than 22 per cent. of clay. They set under
water when half their weight consists of clay. The
proportion of sand used with Roman cement should
not much exceed that of the cement. When em-
ployed for external coatings of buildings it is apt
to effloresce and become unsightly.

59

stance. But it is also known that objects made of unmixed Portland cement from the works of some of the best makers will sometimes keep good for nearly twenty years, and then crumble to pieces even when not exposed out of doors at all. Of course explanations of these failures are forthcoming. They are generally attributed to carelessness in the manufacture of the cement, or in the selection of the materials for it. But if they occur, as they have done, with cements that have stood very well the ordinary mechanical tests, how can any cement of this kind be entirely depended upon for durability? Twenty, thirty, or even fifty years is far too short a time to test the lasting property of a building material of this nature. The use of Portland cement in pavements and for architectural ornaments is not attended with much risk, and for such purposes it is very suitable. The capital employed in the manufacture in Great Britain is probably near two millions sterling. For American cements, see ROSENDALE.

Portland Cement.-This is considered by far the most important of the stone cements. It is an artificial product, named from its resemblance to Portland Stone, but is much more largely used than Roman cement. In the manufacture of Portland cement on the banks of the Thames and the Medway by the wet process, three parts of white chalk are mixed with one part of clay or mud from the lower reaches of these rivers. The two substances, along with water, are placed in a wash mill' in which strong revolving knives or cutters reduce the whole to a creamy 'slurry' or slip. The slurry then passes by gravitation to backs or reservoirs. There it is allowed to settle for some weeks, when the superfluous water is removed by decantation. The mixture is next dried on heated iron plates or on the floor of a heated chamber, and then burned in kilns. Finally it is ground to a fine powder. Modifications of the wet process by which the large reservoirs are dispensed with have been introduced in recent years. In other parts of the country Portland cement is manufactured by the dry process from the hard limestones of other formations than the chalk, along Plaster of Paris (see ALABASTER and GYPSUM). with clay or shale. These limestones are crushed-This material is used for cementing marble and small, mixed in the proper proportion with clay alabaster in much the same way as mortar is in or shale, then roughly burned, and ground to brick-work. It is also employed for uniting the powder. This powder slightly moistened is passed separately moulded pieces of any large object cast through a pug-mill, and then made into bricks, in the same material. Sometimes it is selected which are afterwards burned in kilns and reduced to for fixing metal mounts to glass. powder.

Since Portland cement is hardly ever employed in the pure or neat state, its strength is perhaps best tested when it is mixed with an equal weight of sand. The best cement so mixed and moulded in the state of a stiff mortar, into any convenient shape, when tested after the lapse of seven days, during six of which it is customary to keep it immersed in water, exceeds in tensile strength 200 lb. per square inch, and in crushing strength, tested by 1-inch cubes, 1000 lb. for the same area. Its strength in the unmixed state is much greater. Much of the Portland cement made is, however, little more than half as strong as the best kind. Roman cement of good quality mixed to the same extent with sand as the above, and tested under the same conditions, has on an average a tensile strength of 30 lb., and a crushing strength of 200 lb. in each case per square inch. Portland cement is slow in setting compared with most varieties of Roman cement. Both Portland and Roman cement form hydraulic mortars-that is, they set under water. No mortar will do this which contains less than 10 per cent. of silica.

Till close on 1840 Portland cement was hardly known, but the use of it has extended rapidly, especially in recent years. Its most important application is in the construction of docks and harbours, many of which are partly or wholly built of it, mixed with sand and broken stones, in the form of a concrete. In this state, or simply mixed with sand, it is also much employed for other purposes where strength and durability are required. Owing to the nature of some of the extensive engineering works in which Portland cement is largely used, it is plainly of great consequence that its properties should be thoroughly understood. Numerous failures with it have taken place. The chemical investigation into the case of the Aberdeen docks in 1887 distinctly showed the deleterious action of sea-water upon this sub

Scott's Selenic Cement consists of burnt limestone mixed with about 5 per cent. of sulphate of lime in the form of plaster of Paris, and ground to powder. The presence of the sulphate arrests the slaking action of the lime, causes the cement to set more quickly, and admits of more sand being used with it than ordinary lime does. This cement has been a good deal used for plastering, and to some extent also for mortar.

Keene's Cement is made by saturating plaster of Paris in small lumps with alum and recalcining it. It then forms a hard plaster for the projecting portions of halls and rooms, such as pilasters, columns, and skirtings. It is capable of taking a high polish.

Parian or Keating's Cement somewhat resembles Keene's. In its manufacture borax as well as alum is added to the plaster of Paris. Martin's Cement is another kind, with plaster of Paris for its basis, but instead of borax, carbonate of potash is added, and sometimes hydrochloric acid as well. With the exception of Scott's, these plaster of Paris cements are only used in plastering or other internal work-not for mortars.

Mastic Cement, consisting of a mixture of burnt clay or limestone in a powdered state, with boiled oil and litharge, was more in use formerly than now; but though expensive, it is an excellent material for preventing the admission of rain-water at certain joints about buildings, such as where wood and stone work come together at windows. It was also used for covering external mouldings.

Rust or Iron Cement.-Joints in iron-work, such as those for hot-water pipes, are filled up with a cement of iron borings or turnings, mixed with at least 2 per cent. of sal-ammoniac. Sometimes sulphur in powder is added. The iron oxidises and forms a firm joint.

Sulphur Cement. For jointing earthenware pipes, and occasionally for fixing bars of iron into stone, a cement is made of sulphur, resin, and brick-dust. It is a cheap but not a strong cement where metal is concerned.

Water-glass Cements.-For furnaces one kind consists of burnt and unburnt fireclay made plastic with silicate of soda or water-glass. Another cement, capable of standing a high heat, is formed of asbestos powder made into a paste with silicate of soda. The same silicate mixed with ground glass makes an acid-proof cement.