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'"g atl Ulan ieter and elevation as the niches ; this arch forra-

^SficafT 1,111106 ' Above these the wall sustains a liemi-^'°rbei a ^° me > plan being a circle within an octagon.>p 0rt are not employed at Santa Sophia, but the arches•N do m Sphering over, which forms the circular base of?' v i<led ,e ' ^ le base are eight windows, each window beingN 'lorn 1 ^ le centre by a column supporting two small arches.0r >e en ( ] 6 ’ tse R is built with a double row of pipes, hollow atReived P°i n ted at the other, so that the point of one is

1,1 as pir h*' 16 bollow of the preceding one, continuing thus8t >d th e ' . unt!1 tlie y finish at the top. Both the exterior

In l2qo er * 0r °I tbe dome are covered with mortar.

* ^isa n ’ the cathedral of Santa Maria del Foire, was begunNfs a p t y the celebrated Arnolfo Lusii ; but he died twot 0 u : r > and no architect could be found, who would under-Nor had X d CU,te t * le ^ ome upon the vast plan that its pro-it consequently remained unfinished forV ° (; ati 0n an< ^ twenty years ; when, in a professional con-^Hetio ' ilip Br »nellesBhi was permitted to attempt itsW* {See Brunelleschi .) Notwithstanding thes h e 16 niet "'bh, and the vapouring sarcasms withc cll etn e treated by his contemporaries, who held his

tatted tt im practicable, he carried on the building, andis 0t L q-p. lli uupola, in a manner worthy of his great repu-j w h* c h is octangular, and of great elevation,

h ^Pport. 0 / t ' vo va ults, with a vacancy between them ; anda Utt i'e Sij(;g Merely by the springing wall, without the aid of

fp 11 H *’

though

its dimensions exceed those of all the

, titer’ ° tQan domes, with the sole exception of that of

1 lig ,

buiJt B ®ter’s, at Rome , is the largest temple(i 8| ttic ess -' 11 w as begun by Bramante , in 1513, and carried'p 6 latter' V p ^7 Raphael, San Gallo, and Michael Angelo ,Ip 8 ^ u fiowin w b 0£ n designed the dome as it now appears.

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ln ,g description, extracted from the “ Encylopedie(i to fy’ an d the “ Penny Cyclopaedia,” will enable the'lit N do 11 * 1 Sotue Idea of this superb work,tout'd do 1116 ’ yb'eb is double, is circular on the plan. Thetop i'Q» s me ia constructed on double consoles, instead of/lie double consoles are crowned with a smalllira °I tvhn ln ° an i m P 0St for eight arches, from the upper'W 1 avbi c |, C . s P r ' n gs the dome ; on the top is a lantern-p I'ad l 1S not apparent externally. Up to this timeb t ; p ete f’s f e -S constr ucted on walls and corbellings, but in8i| ( | e ter’ 8 a Rome a new plan was adopted. The dome ofl!i t “° f eet 8t ands upon four piers, 61 feet 11 inches high,‘ ar clie s , jT ln ches thick, measured in a straight line with'ona the arches spring the corbellings, which arean entablature. Upon this entablature is a

ft 1 ? 4 by

NT The

'''clip' The P lnt b is externally an octagon, and internally aatnj t f xt0rn al diameter of the octagon is 192 feet 95 29^ part of * ntern al circle 134 feet 8^ inches; the^ fp ’ !< -‘t 3 j . tle wall, between the octagon aud the circle,N s ! in c ] C les ' . the plinth is a circular stylobate,1 y a ci r leS i This thickness is divided into three

!| Nil jNacb s ';j ar Passage 5 feet 10 inches wide ; the twoNn,, Nt 7), • e °f this passage are, respectively, the internal1 ^all thick, and the external 8 feet. In the

(,f llt ti a ^ ^'glus 6 smaller passages, 2 feet 10 inches wide,

11,^8 fU'* of steps communicating with the four spiralin„j 01 ate, 4, ' n the thickness of the wall of the drumh l ?a bireu . 0ve the circular stylobate, which is 12 feet

< 'Util, <=> . ’ 'S nlnppH tta drnm which is 10

ar e , ® the

placed the drum of the dome, which is 10measured to the inside line of the pilasters,78 ~r ' nter ior of the dome. The pilasters them-,.. leet thick in addition. The construction isof brick. The interior is4 B

fragments

formed with bricks stuccoed. Externally the work is facedwith thin slabs of travertine stone. The drum is pierced with16 windows, 9 feet 3f inches wide, and 17 feet high. Thewalls are strengthened on the outside, between the windows,with 16 buttresses, constructed with solid masonry. Thesebuttresses are 13 feet 3 inches wide, and 51 feet 6 inches inheight from the base to the top of the entablature. Eachbuttress is decorated and strengthened with half-pilasters,and terminates with two coupled columns engaged, thediameter of which is 4 feet; the order is Corinthian. Whenthe base of the dome had been built to the height of theentablature of the drum, Michael Angelo died ; but sometime before his death he had caused a model to be made, withample details, to which he added drawings and instructions.Alter his deathPirro Ligorio and Vignola were appointed thearchitects. Giacomo della Porta, the pupil of Vignola, fol-lowed his master as architect to the cathedral : but althoughthe designs ot Michael Angelo were strictly followed, thedome itself was constructed under the pontificate of Sixtus V.Sixtus gave Giacomo della Porta as a colleague, DomenicoFontana , by whom the dome was constructed.

“ On the constructions of Michael Angelo a circular atticwas first formed, 19 feet 2\ inches high, and 9 feet 7 inchesthick. This attic is strengthened externally by 16 projections,2 feet 11 inches deep, and 6 feet 4^ inches wide, placed overthe buttresses of the dome ; on the attic rises the doubledome, the internal diameter of which at the base, is 138 feet5 inches. The curve externally is an arc of a circle whoseradius is 84 feet 1.62 inches. To the height of 27 feet 8 inchesfrom the attic the dome is solid. At the base the thickness is9 feet 7 inches ; and as the external dome is raised higherthan the internal dome, the thickness is increased as the curveascends, so that where the dome is divided the thickness is11 feet 4 inches. The circular space which divides the twodomes is 3 feet inches wide ; the internal dome is 6 feet4 inches thick ; and the height from the attic to the openingof the lantern is 83 feet 10 inches. The diameter of thelantern is 24 feet 10 inches. The external dome is 2 feet10^ inches thick, where it separates itself from the internaldome ; and it is strengthened externally by 16 projectingbands of the same thickness. The dome is pierced with threerows of small windows, as the curves of the dome are notconcentric, the space between them becomes wider as it rises ;so that at the opening of the lantern the space is 10 feetwide. These domes are joined together by 16 walls or spurs,diminishing in thickness as they ascend to the lantern ; atthe base they are 8 feet thick, and at the summit 3 feet.The base of the lantern is arched, and pierced with smallwindows. Above the two domes is a circular platform, sur-rounded with an iron gallery. In the centre rises the lanternon a stylobate broken into 16 parts, forming projectingpedestals, above which are buttresses similar to the buttressesof the drum, decorated externally with coupled Ioniccolumns, 17£ inches in diameter. The space between thebuttresses is filled with arched openings, which give light tothe lantern. The external diameter of the lantern is 39 feet ;the internal diameter 25 feet 6f inches ; and the height fromthe platform to the top of the cross is 89 feet 7^ inches.The whole height, from the external plinth of the dome tothe cross, is 263 feet. The total height internally, to the topof the dome of the lantern, is 387 feet.

Sixtus V. covered the external dome with lead, and thehands with bronze gilt. During the construction of the domeit is believed that only two circles of iron were placed roundthe masonry, one of which was placed on the outside of theinternal dome, at about 36 feet from its springing, and onefoot above the division of the domes. The bands of iron of