See Introduction to the sketchbook for Turner’s new gallery behind his house in Queen Anne Street West, opened in 1822.
Drawn with the sketchbook inverted, the main design here is for a joist and its moulding in section. There is a smaller outline, related to the notes on heating which read:
Flues from the Back Parlour or Kitchen to warm the Gallery | Ventilation of Gallery – and the Blinds to bow and set behind | a moulding to exclude the | Sun’s rays
Turner’s idea for heating sounds practical and in keeping with his economical nature. His specifications for blinds and moulding must relate to the sketch of a wall of pictures with blinds and a deep moulded cornice on folio 46 verso (D07043; Turner Bequest CV 42a). These schemes for protecting pictures from glare from roof lights all seem rather grand and expensive; were they ever carried out? Latterly, Turner used a cheaper solution – herring nets stretched across the ceiling to filter the light.
Gage suggests that Turner may have got the idea for blinds or nets from his visit in 1819 to the Brera, Milan, where they were widely used in the galleries, or from his reading of Leonardo da Vinci.1
Gage 1969, pp.162–3, 263 note 123; Leonardo, Trattato, 1817 ed., pp.70, 336, 357.