From Adam's rib.

The Great Room of the Royal Society of Arts in London has undergone many changes since it was first designed in the eighteenth century by the Adam brothers. The latest combines the merits of the original with modern technology.

The Royal Society of Arts was founded in London in the middle of the eighteenth century as the Society for the Encouragement of Arts, Manufactures and Commerce, and by the early 1770s, the Society was rich enough to commission a chunk of the Adam brothers' Adelphi development as its headquarters. In the intervening two and a half centuries, the building has been a good deal knocked about as succeeding generations of Fellows changed the decisions of their predecessors. A couple of years ago, John McAslan & Partners were appointed as house architects to try to bring some coherence to a haft mess set in the Adams' elegant framework.

They want to restore a sense of coherence to the place, and to reinterpret its essentially fine qualities. Their most important intervention so far has been the reworking of the Great Room, the RSA's lecture theatre. A few years after the building was occupied, the Room was decorated by James Barry with large canvasses depicting the progress of humanity from Classical times to the eighteenth-century present. Though the chamber itself has undergonne many alterations, this great and slightly dotty frieze has dominated the Room from those days to these, causing many happy moments of reflection in the duller lectures.

Before McAslan's started work, what had looked extremely up-to-date in the 1970s was looking distinctly dingy, faded and worm out with its cinema-like seating and a clumsy great projection box at the back of the space. The Room was originally intended to be top-lit and perhaps the most important change has been to return the volume to perception of the sky and the elements which the first Fellows enjoyed, but which had been effectively blacked out since projection of images by lecturers became commonplace, The new cylindrical central rooflight is perhaps the most obvious change, which allows you to see the heavens from everywhere in the Room (except when the light is obscured for a slide projection session). The cylinder is not just a daylighting device, but like any new installation of its kind, incorporates air-conditioning extract and a range of artificial illumination effects.

The other most obvious change is the removal of the old projection box, which has been replaced by a contemporary remotely operated device which takes up no more than the depth of the long blocked-up fireplace at the back of the room. The old raked floor has been replaced with an oak one and the new dark green seating has been made into continuous rows, with side aisle carpets of rather bluer tint than the seats. The bluish-green palette is carried over the walls, where it is intended to set off the Barry paintings and suppress Arthur Bolton's rather mawkish 1920s version of Adam. What the new architects would really like is to line the walls under Barry with calm, undecorated wood panels.

This proposal is a good one, but perhaps it should wait until the RSA can find money to implement other parts of the architects' calm, rational and sympathetic scheme for bringing the needs of the close of the twentieth century into creative conjunction with the original elegant set of chambers. The Great Room is an excellent beginning.