DOM
278
DOM
which this circle is composed are 3 inches wide by 1| inchthick. A similar circle is placed about the middle of thesolid part of the dome at about 17 feet 6 inches above thespringing of the internal dome. Near the top of the internaldome there are several holes, at the bottom of which uprightiron bars appear. These bars are said to be the connectingrods which keep together other circles of iron placed atdifferent heights within the masonry, which are finally ter-minated by a circle round the eye of the dome.
“ The domes were constructed with such haste, that suffi-cient time was not allowed to the work to form solid beds asit was carried up, in consequence of which a great numberof vertical settlements took place, and the circle of ironround the internal dome was fractured. To obviate the dangerarising from these settlements, six circles of iron were placedround the external dome at different heights, and the brokencircle of the internal dome was repaired. The first circlewas placed above the cornice of the external stylobate, orcontinuous plinth, on which the buttresses stand ; the secondcircle was placed above the cornice of the buttresses ; thethird, above the attic, at the springing of the external dome ;the fourth half-way up the external dome ; and the fifthunder the base of the lantern. A sixth was shortly afterplaced at one foot below where the dome divides itself. Theiron bands are flat, from 16 to 17 feet long, 3^ inches wide,and 2f } inches thick. At one end of the pieces of iron ahole is made ; the other end is turned up, and passed throughthe eye of the next band. The whole of these bands arefixed with iron wedges, driven into the rubble with mallets.Sheets of lead are placed under the iron circles.” (CoupoleEncyclopedic M'ethodique ; ‘ Architecture.’
St. Paul’s cathedral, London , the workmanship of thegreat Sir Christopher Wren , was begun in 1685, and finishedin 1710. “The dome is placed over the intersection of thefour naves. The ground plan is a regular octagon, each faceof which is 44 feet 8f inches wide : four of these sides areformed by the four great arches of the naves ; the other foursides are formed by false arches of the same size ; in each ofthese arches there is a great niche, the base of which is piercedwith two arches. By this means eight supports are obtainedinstead of four, and the corbellings do not project too much,as in other similar constructions. The corbellings gather in acircle, the diameter of which is 104 feet 4 inches, the octagonbase being 107 feet. The corbellings are surmounted by acomplete entablature, 8 feet 3 inches high, decorated withconsoles. The drum is set back 3 feet 2\ inches from theface of the frieze, and this intermediate space is occupied bytwo steps and a seat. The cornice is 98 feet 9|- inches fromthe pavement. The height of the drum from the top of theseat is 62 feet 6^ inches to the springing of the internaldome. The wall forming the drum is inclined internally4 feet 11^ inches, or about the 12th part of its height. Thiswas designed by the architect to increase the resistance ofthe walls to the united pressure of the large internal vault,and the conical dome which carries the lantern.
“ The interior of the drum is decorated with a continuousstylobate, on which is an order of Corinthian pilasters. The32 spaces between the pilasters are filled with 24 windowsand eight large niches. Externally the drum is decoratedwith an order of 32 Corinthian columns engaged, which areunited to the wall of the drum by eight solid constructions inmasonry. In each space between the constructions there arethree intercolumniations, the columns being joined at theirbases by walls pierced with arches. The external colonnadeis surmounted by an entablature ; behind this is a terrace,formed by the recessing back. The attic is 22 feet 4^ incheshigh from the too of the balustrade to the under side of the
dr ® 19
cornice of the attic. Above the internal order ofrises the interior dome, the diameter of which at tn^ to p o'
ing is 102 feet 2| inches by 51 feet in height, ^.^esthe dome has a circular opening 14 feet lOj 1
ter ® 9
opening
diameter. eXt e ‘"i
“ Above the attic are two steps, from which tim ^dome springs. The external dome is constructedcovered with lead, and decorated with projecting® 1 ® ^.jth 9panels, curved at the ends. This dome termin' 1 e c ; rC ul arfinishing which joins the base of the lantern : O' , gfS tb®gallery formed on the finishing is 274 feet 9 inches na> C ,lpavement of the nave. The lantern is supported o ^ >v liic’tower, terminated by a spherical dome. This t0<v * g jts e *is joined to the internal dome at its base, diseng a ° ^giflijfrom it at the height of 8 feet 6 inches above the sp^ j g gof the same. The perpendicular height ol this to ^ tb efeet 9 inches, and the walls are inclined 24 degree®^ 1 i® c |perpendicular, the diameter of the base is 100 c . 0measured externally, and 34 feet 1 inch at the S P', to"' e .the spherical dome which finishes it. The wallo circd' 3 ,is built of brick, and is 1 foot 7 inches thick, w* g pi,er> c ^rings of masonry, fastened with iron bands. * g f e et pdome at the top of the tower has an openmg^^diameter at the summit. Between the attic and ger ve
the tower are 32 walls or buttresses, which a* 3 __
bear the ribs of the wooden external dome-
the ‘ lon J® t ructdi
Paul’s, Hardouin Mansard , a French architect, c °the dome of the Invalides at Paris . The pk" 1 °j n tb e a0 f jnis a square, in which is inscribed a Greek cross; ra' s .of the square there are four chapels. The d° me . ;t > 9 . ethe centre of the Greek cross ; the base suppo® g ;| e s, * yoctagonal figure, with four large and four sma. ^dome, which is double, rises from a s P r * n S' n ” 0 nst'' u !V l lcommon to both. The lower or internal dome . .wii
Cyclopedia.About the
with masonry is spherical. The outer dome isform, constructed of stone at the base, and o
dome oJ t
of* s Pwbof'br s!> ul;
It is framed of wood, and covered with lead,. 1 v q’pe jaLondon , but the construction is much heavier- ^ n {etheight to the top of the cross which surmounts t
330 feet.
formerly the
U 0 1
:bU*V
St. Genevieve, was built by J. G. Soufflot, vv^i ^ p,o"’ 3himself by his architectural works, in the reig n -jj a rs,
The dome, which is lofty, is sustained by f° Pj| g( j up pl-over the cross parts. The angular spaces are . c j, c)pendentives, terminating in a circular ring, ( ’ n ^ j a tt eldrical wall is built, supporting the cupola. \}
an excellent example ; it being morediameter, and only a foot in thickness. . ^fie
A new material has been lately employe 1 - 1 ^ g t , xtion of the dome of the church of St. p/^yafie® & e . ^ jF;burg, erected under the direction of th r n is S iren -ferrand. An account of the construction j a® e
ticular it is similar to St. Paul’s,
Of wooden domes, that of the Halle
Godwin as follows:—“ The walls of the ^ 0 f sto® e o f d 1 ®
,-b® 1 ! 'top ^
up in solid construction of brick, with tie to t ,
and are above 8 feet thick. On the leve t j l6 dr"® ’^lii®^cornice of the circular colonnade which g" feet 0 r o®®is a series of twenty-four cast-iron n s > un s q ul \rest on a cast-iron plate 7 feet wide, w 110 *:g 9 are j jthe circumference. At their head all the wh'® 1 gjvi® 9 ,,a horizontal plate or curb, 6 feet 3 inches' r ibthe periphery of the dome. At this heig _ ^ jeep'into 2, the one part about 12 feet 6 inc