Imagination.

Robinson' Crusoe's diary is in Berlin, lying on a forgotten shelf in the State Library of Prussian Cultural Heritage.  So claims David Caldwell of the National Museum of Scotland.  The library is busy: the same faces have been coming here for a decade.  There they are behind the encyclopedias on the top floor, beneath the terrace with its globes as tall as men.  Each desk is an island kingdom. They come here to write: a page a day when things are going well; half a sentence when they are not.

Caldwell spent a month on this archipelago.  All he found was an angular, pointed piece of bronze, 1.6 centimeters long.  He is certain it must have be part of Alexander Selkirk's dividers, from his navigation equipment.

The diary that the stranded pirate wrote in his solitude ended up in the collection of the Duke of Hamilton but was later auctioned to the nascent German empire.  The first novel in the English language was based on it.  The published confection has as much imagination as truth in it:  Alexander becomes Robinson; the Scottish son of a cobbler became a merchant's son from York who ignores the advice of his father; four years and four months become twenty-eight years, half a lifetime.  The pirate Selkirk becomes the plantation owner Crusoe who constantly struggles with a restless desire to travel to distant lands, but as soon as he achieves this, yearns for his homeland.  

There is an occasional rustling in the magazine section, and in the evening, when the rows are lit up, the blinds at the glass front of the library ar whipped round as if in a little dance, fragmenting the the panoramic view on to an empty square.  In the manuscripts section, they are sifting through the inventory.  On 4 February 2009, a spokeswoman announces, We have searched all the relevant catalogs and have not found what we were looking for.  It is almost certain that Selkirk's diary is not in our collection.

Writers have it much easier than archaeologists.

Judith Schalansky, from Pocket Atlas of Remote Islands: Fifty Islands I Have Never Visited and Never Will