The revolving floor for London's highest restaurant is ready to be installed and here , executives of Ransomes and Rapier , the Ipswich firm which built it , are seen trying it out at their works . This is how dining will be in the restaurant more than 500 ft up in the Post Office radio and Telephone Tower now going up in Bloomsbury , London . the first diners found that when the floor was set in motion pennies placed on edge stayed that way and a glass of water filled to the brim was not spilled . The floor has an outside diameter of 64 ft with a 10ft 6ins wide revolving section. When the restaurant is completed diners will step from the lifts to the stationary section , then to the slowly moving outer ring. The restaurant windows will go round with the floor , so the diners will get an ever-changing panoramic view of London . The structure is now bwing taken to pieces at the Ipswich works and will go by road to the site . 2 November 1963