The essential difference between them is that the mathematical elemaerd of a dome is not an arch of any uniform breadth, but one whose breadth, and therefore weight, decreases upwards to nothing, being in fact a lune enclosed between two meridians very close together. And it was shown in the R.I.B.A. paper, and also by models exhibited, that a dome is stable with a thickness of only ’ 023 of its diameter, while an independent round arch or a barrel vault requires three times as much thickness, or O72 of its diameter. Therefore a barrel vault 100 feet wide must be 7 feet thick to be stable, while a dome of that diameter need only be 27 inches; besides which, the strength of the dome can be increased to almost any extent by building in iron bands in the lower courses, while a barrel vault cannot be so helped. Bands would be of no use whatever in a dome above 52° from the top, as the pressure above that point is entirely inward, assuming it to be tied there, and from thence it gradually increases towards the bottom, where the tension is ∙215 of the weight of the hemisphere. It may seem paradoxical that it should be less there than at 52’; but the explanation is that the tension bears a higher proportion to the weight in a thin dome than a thick one, and it was an infinitely thin one which had the tension of *3 of its weight at 52’; and such a dome cannot be carried lower without bands. In a dome of the required thickness ties would have very little to do above 68°.

As the tension at the bottom is rather more than a fifth of the weight, a dome of proper thickness would be stable standing on a conical drum, with a slope inwards of about 1 to 5, or 12°, of which the tangent is *215, if the drum itself has foundations which cannot spread. The thickness requisite, and also the tension at the bottom, may evidently be greatly diminished by gradually tapering the dome upwards. If it is half as thick at the top as at the bottom, with the thickness increasing downwards as the height, it need only weigh ∙⅛ of the lightest uniform dome of the same size, and only need be 20 inches thick at the bottom for 100 feet diameter.

Pointed domes are also much stronger than hemispheres, having lost the flat top which has the greatest bursting pressure. A dome generated by the revolution of an equilateral arch, or one of 60°, requires a thickness only≡O137 diameter, or 16∣ inches for 100 feet; and one of 70° requires 20 inches. The tension at the bottom of a 60’ dome is only ’ 15 of its weight, which weight, however, is 1372 of a hemisphere on the same base, their heights being as 1 ’ 73 to 1.

For the same reason pointed domes are fittest for carrying a lantern, but they are not much benefited by tapering, having already lost the most oppressive part. The Florence dome, across the flat sides of the polygon, is about 70’ of the circle of its curvature. It is shown in the R.I.B.A. paper that both in hemispherical and pointed domes the weight of the lantern they will carry varies practically as the cube of the thickness. Moreover a lanterned dome requires tieing much higher up than a plain one. In short, the cone is the only proper way of carrying a stone lantern. The cone at St Paul’s has a great chain round the base, which is probably superfluous, as the drum below it seems thick enough to contain the requisite slope, and visibly leans inwards besides.

Ribs inside a dome weaken more than strengthen it, as some persons imagine, unless they are themselves deep enough to be stable as independent arches, or unless they decrease in width and weight upwards like a lune, as those in the Pantheon do, which also is so enormously thick at the haunches that it has superabundant stability. Some of the Indian domes are thick enough for arches, and they have neither eyes nor lanterns. Polygonal domes may be considered as composed of a small number of widish lunes, and only differ from round ones in being rather weaker for any given thickness and size.

Domes require no wooden centring to build them on as arches do, until you get near the top, i.e., so long as each stone laid on the ring of stones below it will not slide inwards. Aud if they are notched to prevent sliding the whole dome may be built without centring. The dome of Mousta in Malta was so built in this century by a common mason, who must, however, have been a man of genius. There would be no difficulty in building a dome of almost any size of bricks or stones, with the help of hoop iron in all the lower courses up to about 22’ from the bottom, and then less up to 52“, and higher if it has to carry a lantern. There is no masonry dome in the world wider than 142 feet. But there have been several larger iron ones, which are an easy piece of engineering, inasmuch as iron has enormous tensile strength, while stone has very little, and mortar practically none; and all the calculations above mentioned assume the domes to be composed of narrow lunes having no lateral bond or tie; but on the other hand all the stones are assumed to go right through the thickness and not to be liable to crush at the edges. Building the lowest courses with horizontal beds, which some architects suggested, was shown to be exactly the opposite of what is mathematically required, as there would be nothing to prevent their sliding over each other, whereas the essence of dome-construction is that the lower courses should confine the upper. It is not however practically expedient to make the beds lean inwards so much as to involve acute angles of the stones, as such angles in stone will bear very little pressure. Brick domes over wells or tanks, which should always be round for strength, are usually built on mere mounds of earth for centring, and they are always of flat section, or only about the upper half of a hemisphere, and are consequently stable with very little thickness, as the earth round them forms a strong abutment.

The following inside diameters of the largest domes in the world are given in SirE. Beckett’s Book on Building:— [table]

In Rome, Domenichino obtained employment from Cardinals Borghese, Farnese, and Aldobrandi, for all of whom he painted works in fresco. The distinguished reputation which he had acquired excited the envy of some of his contemporaries. Lanfranco in particular, one of his most inveterate enemies, asserted that his celebrated Communion of St Jerome (painted for the church of La Carità towards 1614, for a pittance of about ten guineas, now in the Vatican Gallery, and ordinarily, but most irrationally, spoken of as the second or third best oil picture in the world) was an imitation from Agostino Caracci; and he procured an engraving of this master’s picture of the same subject (now in the Gallery of Bologna), copies of which were circulated for the purpose of showing up Domenichino as a plagiarist. There is in truth a very considerable resemblance between the two compositions. The pictures which Zampieri painted immediately afterwards, representing subjects from the life of St Cecilia, only increased the alarm of his competitors, and redoubled their injustice and malignity. Disgusted with these cabals, he left Rome for Bologna, where he remained until he was recalled by Pope Gregory XV., who appointed him principal painter and architect to the pontifical palace. In this architectural post he seems to have done little or nothing, although he was not inexpert in the art. He designed in great part the Villa di Belvedere at Frascati, and the whole of the Villa Ludovisi, and some other edifices. From 1630 onwards Domenichino was engaged in Naples, chiefly on a series of frescoes (never wholly completed) of the life of St Januarius in the Cappella del Tesoro. He settled in that city with his family, and opened a school. There the persecution against him became far more shameful than in any previous instance. The notorious so-called “Cabal of Naples ”— the painters Corenzio, Ribera, and Caracciolo,—leagued together as they were to exclude all alien competition, plagued and decried the Bolognese artist in all possible ways; for instance, on returning in the morning to his fresco-work, he would find not unfrequently that some one had rubbed out the performance of the previous day. Perpetual worry is believed to have brought the life of Domenichino to a close; contemporary suspicion did not scruple to speak broadly of poison, but this has remained unconfirmed. He died in Naples, after two days’ illness, on 15th April 1641.

Domenichino, in correctness of design, expression of the passions, and simplicity and variety in the airs of his heads, has been considered little inferior to Raphael; but in fact there is the greatest gulf fixed between the two. Critics of the last century adulated the Bolognese beyond all reason or toleration; he is now regarded as commonplace in mind and invention, lacking any innate ideality, though undoubtedly a forcible, resolute, and learned executant. “We must,” says Lanzi, “despair to find paintings exhibiting richer or more varied draperies, details of costume more beautifully adapted, or more majestic mantles. The figures are finely disposed both in place and action, conducing to the general effect; whilst a light pervades the whole which seems to rejoice the spirit, growing brighter and brighter in the aspect of the best countenances, whence they first attract the eye and heart of the beholder. The persons delineated could not tell their tale to the ear more plainly than they speak it to the eye. The Scourging of St Andrew, which he executed in competition with Guido at Rome [a fresco in the church of San Gregorio], is a powerful illustration of this truthful expression. Of the two works of these masters, Annibale Caracci preferred that of Domenichino. It is said that in painting one of the executioners the artist actually wrought himself into a passion, using threatening words and actions, and that Annibale Caracci, surprising him at that moment, embraced him, exclaiming with joy, ‘ To-day, my dear Domenichino, thou art teaching me.’ So novel, and at the same time so natural, it appeared to him that the artist, like the orator, should feel within himself all that he is representing to others.” Domenichino is esteemed the most distinguished disciple of the Caracci, or second only to Guido. Algarotti preferred him to the greatest masters; and Nicolo Poussin considered the painter of the Communion of St Jerome to be the first after Raphael. His pictures of Adam and Eve, and the Martyrdom of St Agnes, in the Gallery of Bologna, are amongst his leading works. Others of superior interest are his first known picture, a fresco of the Death of Adonis, in the Loggia of the Giardino Farnese, Rome; the Martyrdom of St Sebastian, in Santa Maria degli Angeli; the Four Evangelists, in Sant’ Andrea della Valle; Diana and her Nymphs, in the Borghese Gallery; and the Assumption of the Virgin, in Santa Maria di Trastevere. His portraits are also highly reputed. It is admitted that in his compositions he often borrowed figures and arrangements from previous painters. Domenichino was potent in fresco. He excelled also in landscape painting. In that style (in which he was one of the earliest practitioners) the natural elegance of his scenery, his trees, his well-broken grounds, the character and expression of his figures, gained him as much public admiration as any of his other performances. (w. μ. r.)

The northern shires are not described in the survey.. Nor thumberland, Cumberland, Westmoreland, and Durham are conspicuous by their absence. Lancashire does not appear under its proper name; but Furness and the northern part of the county, as well as the south of Westmoreland, with a part of Cumberland, are included within the West Riding of Yorkshire. That part of Lancashire which lies between the rivers Ribble and Mersey is subjoined to Cheshire; and part of Rutland is described in the counties of Northampton and Lincoln. The reasons which led to the omission of these northern counties from Domesday are not difficult to be understood. Durham and Northumberland had been laid waste by the merciless hand of conquest. The devastations of the Conqueror himself in the winter of 1069-1070, the various inroads of Malcolm, and the vengeance taken by Odo after the murder of Bishop Walcher in 1080, must have left very little in those districts worth the surveying. Lancashire did not then exist as a separate county. Cumberland and Westmoreland had no being as English shires,—their southern portions then formed part of Yorkshire, and they are surveyed in Domesday as such; whilst their northern portions did not become part of the kingdom of England till the reign of William Rufus, having been held by the Scottish kings as a fief ever since the grant by Edmund the Magnificent, on the final overthrow of the old kingdom of Strathclyde. The notion that the northern portions of Cumberland and Westmoreland were conquered in 1072 by William I. is derived from a careless blunder in the work of Matthew of Westminster, who has confounded William Rufus with his father.

The exact time of the commencement of this survey is variously stated. The Red Book of the Exchequer has been quoted as fixing the date at 1080; whereas the Red Boek merely states that the survey was undertaken at a time subsequent to the total reduction of the island to the authority of the Conqueror. From the memorandum of the completion of the survey at the end of the second volume, it is evident, however, that Domesday was finished in 1086. Matthew Paris, Robert of Gloucester, the Annals of Wavert ey, and the Chronicle of Bermondsey give 1083 as the date of the record; Henry of Huntingdon places it in 1084; the Saxon Chronicle in 1085; Simeon of Durham, Florence of Worcester, Roger Hoveden, and Hemingford in 1086; whilst the Ypodigma Neustriae and Diceto state 1087 as the year.

The reason given for taking this survey, as assigned by several ancient records and historians, was that every man should be satisfied with his own right, and not usurp with impunity what belonged to another. But besides this, it is stated by others that all those who possessed landed estates now became vassals to the king, and paid him so much money by way of fee or homage, in proportion to the lands they held. According to the false Ingulphus, the survey was made in imitation of the policy of Alfred, who, at the time he divided the kingdom into counties, hundreds, and tithings, had an inquisition taken and digested into a register, which was called, from the place in which it was deposited, the Roll of Winchester. But the compilation of such a survey in the time of Alfred may be more than doubted; for, with the exception of the statement of Ingulphus, no chronicler alludes to the existence of this register, nor is any mention of it to be found in the records of the time or in those of a subsequent period. Had it been extant in the century immediately preceding the Norman Conquest, it would have prevented the necessity of giving those minute descriptions of land so common among the later of the Saxon charters. Again, the separation of counties is known to have been a division long anterior to the time of Alfred. The confusion in all probability has arisen from a similarity in the title of the two works. The survey of the Conqueror was called Domesday

Book; the register of Alfred had the name of Dome-boc; but the Dome-boc, instead of being a territorial analysis as is Domesday Book, was in reality the code of Saxon laws.

For the execution of the survey recorded in Domesday Book, certain commissioners, called the king’s justiciaries, were sent into every county and shire, and juries summoned in each hundred, out of all orders of freemen, from barons down to the lowest farmers. These commissioners were to be informed by the inhabitants, upon oath, of the name of each manor and that of its owner, also by whom it was held in the time of Edward the Confessor; the number of hides; the quantity of wood, of pasture, and of meadow land; how many ploughs were in the demesne, and how many in the tenanted part of it; how many mills and how many fish-ponds or fisheries belonged to it; the value of the whole in the time of King Edward, as well as when granted by King William, and at the time of this survey; and also whether it was capable of improvement or of being advanced in value. They were likewise directed to return the tenants of every degree, the quantity of lands then and formerly held by each of them, what was the number of villains or slaves, and also the number and kinds of their cattle and live stock. These inquisitions, being first methodized in the, county, were afterwards sent up to the king’s Exchequer. So minute was the survey, that the writer of the contemporary portion of the Saxon Chronicle records—“So very narrowly he caused it to be traced out that there was not a single hide or yardland, not an ox, cow,'or hog that was not set down.”

By the completion of this survey the king acquired an exact knowledge of the possessions of the Crown. It afforded him the names of the land-holders; it furnished him with the means of ascertaining the military strength of the country; and it pointed out the possibility of increasing the revenue in some cases and of lessening the demand of the tax-collectors in others. It was, moreover, a register of appeal for those whose titles to their property might be disputed.

So accurate has Domesday Book been considered that its authority was never permitted to be called in question; and when it has been necessary to distinguish whether lands were held in ancient demesne or in any other manner, recourse was always had to Domesday, and to it only, in order to determine the doubt. From this definitive authority, from which, as from the sentence pronounced at Domesday, or the Day of Judgment, there could be no appeal, the name of the book is said to have been derived. Stowe indeed assigns another reason for this appellation, namely, that Domesday Book is a corruption of “domus Dei book,” a title given it because heretofore it was deposited in the king’s treasury in a part of the church of Westminster or Winchester called domus Dei; the name, however, is plainly English. From the great care formerly taken to preserve this survey, we may learn the estimation in which it was held. In the Dialogus de Scaccario it is said, Liber ille (meaning Domesday) sigilli regis comes est individuus in thesauro. It was formerly kept at Westminster with the king’s seal by the side of the Tally Court in the Exchequer, under three locks and keys, in the charge of the auditor, the chamberlains, and deputy-chamberlains of the Exchequer, till in 1696 it was deposited among other valuable records in the chapterhouse. It is now carefully preserved beneath a strong glass case in the Public Record Office, and can be consulted without payment of any fee.

Various local Domesdays exist, as those of York, Norwich, Ipswich, Chester, and Evesham. The most notable among them is the Domesday of St Paul’s, made in 1181 by the Dean, Ralph de Diceto, and edited by Archdeacon Hale.

In 1783 Domesday Book was published in two volumes, andin 1816 a volume of indices was printed by the Record Commission, to which a very valuable “general introduction was prefixed.” During the latter year another volume appeared containing the Exon Domesday, and the Inquisitio Eliensis, already noticed; the Winton Domesday, comprising lands in Winchester between 1107 and 1128; and the Boldon Book, or Survey of the Palatinate of Durham in 1183. Within the last few years the whole of Domesday has been issued in parts, each part comprising a county, and printed by the process of photozincography, under the scholarly superintendence of Mr W. B. Sanders, one of the assistant keepers of the Public Records.

See Sir H. Ellie’s Introduction and Indexes to Domesday, vol. i. and ii.; Domesday Book, illustrated by Kelham; Descriptive Catalogue of Manuscripts relative to the early History of Great Britain, vol. ii.; History of the Norman Conquest, byE.A. Freeman, vol. v.; Our Public Records, by A. C. Ewald.