40 C O N T E X T 1 6 7 : M A R C H 2 0 2 1 Architectural paint research also established the placement of gilding. By the early-to-mid- 20th century, Dutch metal was applied rather than gold leaf. This, combined with tired blue walls throughout the interior, had left the room looking very dull.The team followed the findings of the architectural paint research to reinstate the gold leaf to the 18th century placement. To the internal plasterwork, specialist decorator Hare & Humphreys carried out an oil gilding process; all surfaces to be gilded were prepared to a smooth finish and painted with an ochre- coloured eggshell paint, followed by a 12-hour size, thinly applied to the surface where gold was to be laid. This was left to cure for a day or until a correct level of tack had been achieved for the gold leaf to adhere smoothly. 23½ carat gold leaf was applied to the surface in sheets using a badger-hair brush. Any excess gold was removed and the surface was burnished using a squirrel-hair brush. During the construction works, an original timber sash frame was uncovered while unblock- ing the bricked-up north-east window opening. The team discovered evidence of older joinery removed when the window was blocked in the 1860s, when the north wing was extended to accommodate larger kitchen facilities. A new large timber sash window was installed to repli- cate the existing, restoring the sense of symmetry intended by Gibbs by centring the fireplace and south window as the axis, with the doors to north and west wing to either side, complemented by very large sash windows on the south side facing Thames riverbank. Further discoveries including the uncovering of the original Portland stone flags beneath the 19th century marble slabs, which match the design of the Portland stone flags below. The marble was an enhancement carried out for the French royal family in exile: the coloured marble closely matched floors at Chantilly. The team decided to retain the existing marble floor finish of polished white Carrara and Belgium black to the central area, and the Rosso Francia tiles were used to repair the border. A focal point of the restoration of the Octagon was the reinstatement of a chandelier, which was lost in 1960s. The water-gilded limewood chandelier was made by Hare & Humphreys, its design based on the only two known photo- graphs of the lost chandelier. Ayaka Takaki is an architect and associate director at Donald Insall Associates. The team followed the findings of the architectural paint research to reinstate the gold leaf to as it was the 18th century (Photo: Richard Chivers) Gold leaf was applied using a badger-hair brush.