Here are the Piranesi drawings that Soane displays so ingeniously on pull-out rods in his picture

Here are the Piranesi drawings that Soane displays so ingeniously on pull-out rods in his picture gallery at home, and a huge canvas painted by his fishing partner, JW Turner, that Soane commissioned for his house but sent back as he didn’t like it, now on loan from the Tate. Like any capricious impresario of special effects, Soane cancelled visits on dull and rainy days.A carriage clock chiming sweetly on the hour at the RA takes us straight back to Soane as a young man. On the wall, his diary entry for 18 March 1778 reads: “At five in the morning set out for Italy.” That Grand Tour began a love affair with antiquities and the classical orders that never ended. By the time the light filters into the basement, where Soane housed a sarcophagus, the atmosphere is faintly spooky – “morbid, very fin de siecle,” says Gough.

Looking up into one of Gough’s sectional ceilings – modelled exactly on Soane – you can see the lanterns that beam light down through three floors cut up with the walkways in Soane’s own home. To warm up the grey northerly light Soane lined these lanterns with amber glass and painted his breakfast room a zingy yellow. Mirrors pasted in the most unlikely places – the back of pictures or bulbous eyes on doors – bounce back light and Gough has hung one of the doors from the museum at the RA. This fantastic precursor of so much of modern architecture is revealed with all the tricks and illusions that traditional Beaux Arts-trained architects, with their love of architectural neo-classicism, ignored and put Soane out of fashion. “Fighting the overblown boudoir classicism under those vast cornices was very un-Soane-like.” Gough’s strong structural installations reduce the impact of the RA to offer us axial routes and vistas as seductive as Soane’s.Then Gough lets us join the Magic Circle to find out what makes Soanian tricks work, and banish Soane’s epitaph – “picturesque” – forever.

“Frankly it would have been easier to do it in the Hayward,” Gough admits. When you think of one’s actual experience of ceilings, you mean wall, ceiling, enclosure and light.”Setting up this exhibition of Soane’s coolly elegant, honed-down classicism in the RA was no mean feat as its architecture enshrines precisely the aesthetic Soane rejected. It was Philip Johnson who declared that John Soane was “really a ceiling architect That’s not trying to make him look small. He also decided to show us how Soane manipulates both space and light by building replicas of the domes at Lincoln’s Inn Fields to demonstrate how they wrap around entire rooms to become the walls.Soane’s pendentive domes, outstretched like bats’ wings pinioned to the corners of the room, turn the ceilings into membranous shelters. The exhibition’s designer, Piers Gough of CZWG, used those dimmer light levels to create pools of light in a rather Soanian way. Worse, many of the architectural perspectives are watercolours which fade under high levels of light, so the four galleries in the RA are purposefully dimmed down.