Half-section and quarter-plan (left), with half-elevation (right), of a 24-bay dome, arranged with apses on the diagonal axes (left) and on the cardinal axes (right)

WRE/5/1/12

c.1690–92

Sir Christopher (1632–1723) Wren, Nicholas (c.1662–1736) Hawksmoor

Pen and brown ink over incised lines with pen shading (no pencil). Thin laid writing paper; large tear with paper loss, upper right, and diagonal tear at upper left, both repaired with modern backing; staining on back with early glue marks. 31.4 x 19.4 cm. Countermark: JJ

{\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 Study, with alternatives, for a dome with domical, apsidal projections in the drum: the left side with apses on the diagonal bays and a pedimented aedicule on the cardinal axis, the right side with this arrangement reversed. Drawn by Wren with pencil calculations by Hawksmoor on front and reverse. Datable, c.1690-92. Scale, 26 ft to 1 inch.\par \par The freehand pen technique, with loosely applied or scribbled hatched and parallel shading lines, and without pencil under-drawing, is characteristic of Wren\rquote s hand in c.1685-95 (see Geraghty 2007, p.11 and nos.79, 155, 262). The abutment of the drum with domical projections derives from Hagia Sophia in Istanbul, partly through the medium of engravings in Guillaume-Joseph Grelot\rquote s \i A Late Voyage to Constantinople\i0 (1683). Some time in the mid-1680s (or soon after) Wren or Hawksmoor copied (or adapted) studies of the Hagia Sophia dome by John Chardin, Grelot\rquote s patron, in two part-plans and a section, now in Montreal; see Du Prey 2000, pp.41-46, fig.29; Jardine 2002, pp.414-20. Internally and externally, the half-domes of the apses, slightly shadowed, would have lent the drum an extraordinary interest (Morrogh 2010, pp.521-22)\par \par Several motifs in the design derive from Wren\rquote s \lquote cubic-parabola\rquote dome of c.1690-91: the thin outer dome, the small lantern and the tripartite windows the drum (see WRE/5, Fig. 6). The design is unlikely to date after work started on the roof of the choir in early 1693 (Wren Society 14, p.109). By then, Wren would have decided on the roof structure around the base of the dome.\par \par In the left half-section a staircase rises over the back of the inner drum, before continuing beneath the outer dome in a quadrant line of iron steps, drawn as small circles. These steps are suspended from platforms cantilevered from the shell of the outer dome beneath lucarne windows. The outer shell is drawn quite thin and was probably intended as masonry construction. \par \par On the left side the apse-projection embraces the vaulted semi-dome of the diagonal bay at triforium level. On the right, the apse is on the cardinal axis and a pedimented aedicule, shown in section on the left side, stands over the diagonal bay. Beneath this bay is the diagonal side of the octagonal lower drum. The only inconsistent feature in the whole study is the apse sketched in side view on the left side; it stands too far out for an apse on the diagonal and is probably a trial for the apse on the right.\par \par The drum has two tiers of windows at different levels, inside and out. In the outer drum they extend from the base of the column pedestals to the under side of the entablature. In the inner drum, where the applied order is smaller and lower, the lower tier is between the pilaster shafts and the upper tier is in an attic, immediately below the inner dome. Wren drew ruled lines through the left section to show how light would pass from the upper tier of windows in the outer and inner drums to the soffit of the inner dome. \par \par Written in pencil by Hawksmoor in reverse, upper left, is a division of \lquote 108\rquote (the internal diameter of the drum in feet) by \lquote 7\rquote , giving \lquote 15\rquote with \lquote 3\rquote as a remainder. This may be a rule-of-thumb estimate for the thickness of the drum as 1/7 the diameter. On the quarter plan Wren has marked \lquote 12\rquote feet across its width (although it scales at about 13 ft). Designs at the next stage have drums 15-16 ft deep; see WRE/5/2/4.\par \par At upper right, in the same brown ink as the drawing, \lquote\i Quid\i0\rquote . Probably Wren trying out his quill pen before starting the sketch.\par \par \b Reverse:\b0\par \par Several calculations in pencil by Hawksmoor, including: top: divisions of 34 (by 3) and 108 (by 12?); centre left, division of 246; centre right, division of 86 (by 5) with \lquote 9 - 0\rquote above it. \par Sketched in pencil at lower left, in reverse sense, is a perspectival section through an arch head with an architrave moulding on the front face; and roughly in pencil, vertically in centre-right, a lintel or frieze with circular motifs.\par \par The \lquote 77\rquote in brown ink (probably eighteenth century) is unrelated.\cf0\b\f1 \par }

Access to the Wren office drawings held at London Metropolitan Archives is available only with advance notice and at the discretion of the Heritage Services Director, London Metropolitan Archives, 40 Northampton Road, London, EC1R 0HB.

WRE/5/2/4, WRE/5/3/9, WRE/2/2/8