Full-height comparative section of the crossing, dome and lantern, with alternatives, left and right, above the cornice of the inner peristyle

WRE/5/3/9

c.1701–03

Sir Christopher (1632–1723) Wren, William (1671–1725) Dickinson

Pen and brown ink over pencil, with amendments and over-drawing in red-chalk, pink ink and pencil. Laid paper, with modern backing paper. 54.0 x 38.8 cm, including small attached sheet (6.0 x 9.6 cm) at top (49. 2 cm high without this), and including an attached triangular flap on right (15.3 x 7.8 cm) with an alternative section above the internal peristyle. No watermark or countermark visible.

{\rtf1\ansi\ansicpg1252\deff0\deflang2057{\fonttbl{\f0\fswiss\fprq2\fcharset0 Microsoft Sans Serif;}{\f1\fswiss\fprq2\fcharset0 System;}} {\colortbl ;\red0\green0\blue128;} \viewkind4\uc1\pard\cf1\f0\fs20 A full-height long section of the dome, from the first bay each side of the crossing to the top of the lantern, with comparative studies of the section above the cornice of the internal peristyle and a final revision in pink-coloured line and shading on the left. Drawn by William Dickinson, but with the pink additions and some pencil probably by Wren. Datable c.1701-03. Drawn scale, about 19 ft to 1 inch (100 ft = 139 mm).\par \par The section records design of the dome nearly as built from its base to the capitals of the internal peristyle. It is experimental above this level, schematic below the crossing arches, and inaccurate at church-floor level, where the first nave bay left of the crossing pier is drawn too narrow. \par \par When Arthur Bolton published the drawing for the first time in 1936, shortly after its acquisition by St Paul\rquote s, with WRE/5/3/10, from a sale of Sir Thomas Phillips\rquote s collections, he observed that the section illustrated \lquote Wren\rquote s method by which the design was kept in a fluid state throughout the process of building\rquote , and how \lquote the construction and major elements of the design were modified even at the last moment\rquote (Wren Society 13, pp.xv-xvi and pl.13). He suggested a date 1704-05, shortly before the \lquote great chain\rquote was installed at the shared base of the brick cone and upper attic of the outer drum. The drawing is probably about two years earlier than this. \par \par The pink revisions were drawn over a left-hand section in brown ink, which itself was a revision of two other sections in brown ink on the right. All three earlier alternatives were drawn by Dickinson, whose hand is apparent from the scale bar and other inscriptions. They are: (i) a half-section on the right showing a modified version of the internal attic designed in c.1695 (see WRE/5/3/5), beneath a high inner dome (its radius marked with a dotted line); (ii) an internal section on an attached cut-out sheet to the right of this, showing a reduced version of the attic and a lower inner dome; and (iii) a half-section on the left which lowers the inner dome still further, blocks the openings of internal attic and reduces the height of the outer dome and lantern. The plinth of this inner dome provides a ledge for internal scaffolding, drawn lightly in pencil (see below). Slots for iron chains at the base of the inner dome and in the wall of the outer attic are lower than in the right half-section. \par \par The brown-ink alternatives postdate the dome in the two authorised engravings of the north and west elevations, completed in 1701 and 1702 respectively (Wren Society 14, pls.10 and 12): they lack the large windows in the outer attic and have shorter internal attic windows, inside and out, above the internal entablature. The cone in these alternatives resembles a timber structure: it rests against the back of the inner dome and stands on the vaulting of the upper attic, and on the left side it passes through the vaulting and lies against a supporting radial wall. Horizontal struts, carried on scrolled brackets, link the cone to the shell of the outer dome. It was probably meant to be in brick as it has no internal tie beams and the inner dome in the main half-section is even thinner (just 1 ft thick compared with 1 ft 6 inches in the fabric). Wren had yet to integrate the cone with the masonry structure below. For this reason, perhaps, Dickinson rendered it ambiguously. \par \par During the summer of 1703 construction reached the base of the internal entablature, and in 1704-05 it moved upwards by 15 ft to the \lquote Great Capitals\rquote of the external entablature (Wren Society 15, p.120). In December 1703 Edward Strong\rquote s masons completed a model of the external entablature (Wren Society 15, pp.101-03). By this time the design would have been finalised at the equivalent level on the inside, at the springing of the inner dome, as internal and external masonry were to be linked structurally by a network of iron cramps (see Campbell and Bowles 2004, fig.139). This system of reinforcement replaced the large slot for the great chain at the springing of the inner dome on the left side of the section. \par \par The pink revision substitutes a thicker cone but does not show the great chain repositioned the base of the upper attic. The freehand shading and hatched technique finds comparisons in Wren\rquote s own freehand pen drawings; see WRE/5/1/12. The thick pencil under-drawing of this revision is also characteristic of his hand; see WRE/5/1/6. The catalyst for this final revision was the lowering of the springing line of the inner dome and the elimination of the internal attic in the brown-ink variant on the left side. Wren now rationalised the whole internal structure by fusing the base of the cone with the inner dome in a single masonry mass, buttressed by stepped radial walls which rise between enlarged barrel-vaults over the peristyle bays. He set the upper attic wall further out to carry a broader outer dome; it rises from a two-step base on a higher, steeper profile to the base of an enlarged lantern. The lantern is carried by the cone on two concentric masonry walls, the inner one forming a central chamber with floor divisions and a domical top. \par \par These final revisions can be dated after the accession of Queen Anne in March 1702. In the summer of that year her first Parliament granted a generous financial settlement for the completion of the cathedral (Campbell 2007, pp.67-69; Higgott 2009, p.169). Without this Wren could not have contemplated the much larger lantern in this revision. \par \par The inner dome was built slightly steeper in 1705-06 and a circular opening was created at the top. Alternatives for a lower and higher inner dome are explored in pencil and incised lines on the left. A dashed pink line at the approximate level of the opening, and the two higher sections, both in parabolic profile, may be preparatory the final design. \par \par In the summer of 1705 the large wrought-iron \lquote great chain\rquote was installed at the shared base of the cone and the outer wall of the attic. At the same time, a large \lquote Truss Scaffold\rquote was installed around the base of the inner dome to support centering for the brickwork (Wren Society 15, p.121; Campbell and Bowles 2004, figs.137, 138). Drawn in pencil on the left side of the section is a sketch for this cantilevered scaffold. Two diagonal lower struts rest on the cornice of the lower tambour and the sill of the peristyle windows; they are linked to three upper struts which connect with beams at the base of the inner dome, immediately above its plinth. No other visual record of this scaffolding survives.\par \par Three dimensions in Dickinson\rquote s hand on the right side of the section give the half-diameters of the dome at their respective points and may be connected with the design of the scaffolding: (i) level with the cornice of the inner peristyle: \lquote\i 52 : 5 \'be\i0\rquote ; (ii) level with the top of the dome entablature: \lquote\i 48 : 5 \'be\i0\rquote ; (iii) at church-floor level: \lquote\i 53 : 6\i0\rquote . \par \par See also Gerbino and Johnston 2009, cat. no.47, p.182, and Higgott 2009, p.169.\cf0\b\f1\par }

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WRE/5/1/12, WRE/5/1/6, WRE/5/2/1, WRE/5/2/5, WRE/5/1/7, WRE/6/2/2, WRE/6/2/7, WRE/2/2/7, WRE/5/2/4