The RIBA received the Palladio drawings as a gift in trust from Spencer Cavendish, 8th Duke of Devonshire in 1894. They had been pasted into 17 large volumes by Lord Burlington about 170 years earlier, and this is how they arrived at the RIBA's headquarters, then in Conduit Street, London. Most were decorated with red lines drawn around the edge of each sheet.
Once at the RIBA the pages on which the drawings were pasted were cut out of the volumes and kept loose in paper covers on the shelves of a specially made tin box marked Burlington Devonshire Collection. However, Lord Burlington's order was carefully preserved. Each of his volumes had a Roman numeral, and the drawings inside were given a running number, so that, for example, XIII/6 was the sixth page of the 13th volume. Burlington had sorted them roughly by building type.
In the 1960s, the drawings were conserved and mounted into cardboard window mounts that were kept in solander boxes. These are large, flat boxes used by museums and archives worldwide to house drawings, named after their inventor, the 18th-century botanist Dr Daniel Solander (1733-82).
Currently the drawings are undergoing further conservation as many have buckled over the years, distorted by Lord Burlington's methods of repair and mounting.
Nowadays the drawings are used by scholars, students, architects and members of the public interested in the scholarship and architecture of Palladio.
The world's finest collection of Palladio drawings may be seen both here online and, by prior appointment, at the RIBA Architectural Study Rooms at the Victoria and Albert Museum.