Stone, too, was chosen to pick up the changing colours of daylight: creamy limestone, as at Doha, or the pale pink Tennessee marble he used for the East Building. But everyday concrete could also be refined to his purposes by matching its colour consistently to local earth, bush-hammering the NCAR slabs so that they resembled weathered rocks, and avoiding visible joins. One of his designs for William Zeckendorf, the flamboyant NewYork property developer who employed him in the 1950s, was the Kips Bay Plaza housing project, two square grids in precast concrete which were meant to revitalise a blighted neighbourhood.
He softened them with arched and recessed windows until they looked like honeycombs. Architecture could heal, too. Once Jackie Kennedy had daringly picked him to build her husband's library in 1964, he became such a feature of America's cultural scene, owlishly sipping his favourite red Bordeaux, that it was easy to forget that only the rise of the communists in China had kept him in America at all. He had come to study in 1934, lured mostly by the films of Bing Crosby and Betty Grable, and had fun. But he was keen to go back until it became too risky for a banker's son to do so.
He therefore took American citizenship, but did not cut the roots. His wife was Chinese; his children had Chinese names. And his imagination had been shaped less by Le Corbusieror Walter Gropius, though he met and admired both men, than by his family's ancient gardens at Suzhou in Jiangsu. There, as a child, he would wander winding paths through fantastic rocks towards pavilions, unconsciously absorbing sightlines and approaches, light and shadow, as well as the framing of views. He did not forget.