bricks in the centre with the names of the maker, usua a slave, and of the owner of the property where the bri kiln stood; to these, in the time of Hadrian and onwar it became customary to add the names of the Consu A sufficient number of stamped bricks were used in ea edifice to record its date with certainty. But, after t transference of the seat of government to Constantinop the decay of Rome set in, and this care was no longer hibited. While the custom lasted, the greatest persons the empire, even members of the reigning family, were r ashamed to have their names thus stamped on their mar factures. The kilns were valuable property, and the wo Prædium, often met with in the history of that peric frequently includes the brick-kiln.

Opus mixtum was another method of construction, which bricks and rough stones were set in alternate laye at regular intervals. It occurs in many parts of the wa of Rome, and in the Circus of Maxentius, A.D. 310. Th style is usually attributed to the fourth century, becau of this dated example in the first quarter of it; but occurs also at Pompeii, which was destroyed A.D. 79, a in many parts of the substructure of the wall of Aurelia which in various places is evidently built upon an earli wall. It may be seen also in some of the foundatio walls of Hadrian's villa at Tivoli, and at Ostia in toml of the second century. It is known in Rome as the sty of the Decadence, because it was much used in late Ir perial times; but it may be properly regarded as a natur development of the mere concrete wall, which forms th core, or central mass of nearly all Roman walls; and like other cheap natural modes of building, it affords itself no evidence of date. It may be added, that it the style of construction most commonly adopted by th Romans in Gaul and in Britain b.

b See Note B, p. 1o.

and Various Styles of Construction.

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Opus signinum was the name given to the peculiar cement used in lining the channels of aqueducts, so as to make them impermeable by water. It was composed of pounded fragments of brick tiles reduced to powder, and mixed with fresh lime. It is still known in Rome by the name of Cocciopesto.

Something must be said on the use of marble at Rome. It is a mistake to suppose that it ever was used commonly as a building material; but it was used as an ornamental facing to temples, palaces, and thermæ, and also in sumptuous private houses; the core of the wall being stone, and laid over with slabs of marble, and sometimes with square or oblong blocks of it. The cornices and columns are of marble, and all that was visible was so, while the main body of the cella, or shrine, was solid stonework, and this sometimes remains when the ornamental portions have been rebuilt. This is the case with some of the churches which are temples converted to Christian use. The earliest mention of marble is about B.C. 150. Up to that time not only the finest buildings, but sculpture also, had been confined to stone. The great lions' heads in the bank of the port of Rome in the Tiber, B.C. 175, are of stone: so are the tombs of the Scipios, and the temples built up to the date A.U.C. 573 had no marble. Monumental arches, such as that of Drusus, were of stone; that of Dolabella on the Cœlian, the earliest dated building of the Christian era, A.D. 10, is of massive Travertine stone. The theatre of Marcellus is of stone. The Colosseum is externally of stone, internally of brick. The round temple, usually called of Vesta, but more properly that of Hercules in the Forum Boarium, and the Mausoleum of Hadrian were overlaid with marble. The magnificent Thermæ of Antoninus Caracalla were cased with marble to a great extent; the brick walls and plaster,

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with the marks of the marble slabs, shew what once were. In the later palaces of the Cæsars on Palatine some of the columns still standing are of s marble, and some shew a marble coating over a st centre. The ruins of the temples supplied many CL tian churches with the grandest marble columns for porting the clerestory walls and for ornament.

The Romans, after the taste for marbles had once set ransacked the distant parts of their empire for every var of them: the names of distinct sorts compose a long the most beautiful and costly coming from Africa. Th was a wharf on the Tiber devoted entirely to the land of such sea-borne stones. This wharf, called the M morata, was found and excavated in the time of Pius and on being cleared from the sands of the Tiber, hibited a vast store of marble blocks in different deg of rudeness and finish, with some specimens of the finest kinds known, now wholly unobtainable. It is lieved also that the Romans imported by sea granite st from the same quarries as are still wrought near the La Verbanus, or L. Maggiore. The Devonshire marble, ca on the spot Pudding-stone, was highly esteemed in anci Rome, and was very scarce there.

CHAPTER II.

ROMA QUADRATA.

IT was the constant tradition of Rome's inhabitants that

their original city was planted on the Palatine Hill, and the presence of the rudest kind of masonry, still visible round portions of an oblong space at the north end of that hill, confirms the tradition. The position of that eminence is clearly defined upon Mr. Parker's map of Rome; it is the most central of the seven hills composing the complete City; the others, as the Italians say, stand round and pay court to her as queen; and when the whole area was filled up, this, the most ancient of all its divisions, still retained something of a sacred character as the original home of the nation. The form of the Palatine is that of a diamond or lozenge-shaped parallelogram, with its upper apex pointing nearly due north; its height above the sea is 170 feet, and its surface contains about sixty-five acres. But the primitive fortifications occupied only a portion of that extent, namely, the north-western, and this did not contain more than onethird of the whole. What was formerly supposed to be a natural depression is found to have been a very wide and deep foss across the centre of the hill at least 100 feet wide and 30 feet deep, separating the northern portion from the remainder of the hill. This trench is discernible as a deep cutting across the middle of the hill. The space so defined constituted the Arx, or citadel of the colony, into which the settlers, living in their huts on the slopes around, could drive their cattle and conduct their families in time of war. The same principles of fortification as those adopted by the first Romans w universally applied by settlers in the Italian peninsu First of all, a hilly site was chosen, and if its sides w not sufficiently steep by nature, they were dug away, scarped into perpendicular cliffs, and against these a w was built up, where necessary, to prevent landslips. T earth thrown down formed a terrace at the foot, and 1 yond the terrace a trench was excavated with a ro usually in the bottom, and the soil thrown up out of formed an agger, or bank. Not the Palatine alone, 1 each of the other hills of Rome, was, as there is reas to believe, originally a separate fortress of this characte and the strong places of Etruria, of which Veii, so long t powerful rival of Rome, is the chief example, were sir larly defended. Usually, each hill-town consisted of thr parts: 1. The Arx, or citadel, on the highest ground, a most strongly fortified; 2. The dwelling portion, or to around the first, and lower down, also with its stro lines of defence; 3. The pasture - ground, naturally larger area than the other two, with a single line of pr tection. And if there was other prominently rising grou near at hand, it was usually occupied as a detached fo for additional security.

The Arx, or citadel of the colony on the Palatine, called by Roman writers, Roma Quadrata. A fragme of Ennius, quoted by Festus, runs, "Qui se sperat Rom regnare quadratæ." One interpretation of this phrase that the wall of circumvallation is of the kind of mason called Opus quadratum, i.e. formed of rectangular bloc of stone. But Dionysius of Halicarnassus, with more pr bability, refers the name to the shape of the first enclosu on the hill,-"Roma quadrata, which means quadrangular a four-sided city. It is, however, this wall-work, now mac visible by excavations, that is so highly interesting from i