Unesco adds Sir Isaac Newton's papers to world register
Details of Sir Isaac Newton's spending on stockings and shoelaces are among the scientist's papers which have been added to a global database of historically important documents.
The Cambridge University collection has been added to Unesco's International Memory of the World Register.
It includes his personal accounts as well as drafts of Principia Mathematica containing Newton's laws of gravity.
The register preserves documents "of outstanding universal value".
The university's collection of Newton's papers is one of the largest in the world and includes correspondence with Astronomer Royal Edmond Halley, who persuaded Newton to publish Principia, his book of mathematical principles.
It also includes Newton's own copies of the first edition of the Principia, published in 1687, which are covered with his corrections, revisions and additions for the second edition.
More personal items in the collection include a notebook written during his time as an undergraduate, in which he lists how much he has spent on items such as wine, the shoestrings that cost him one shilling and 10 pence, and his four shillings and sixpence stockings.
He also appears to have lost 15 shillings at a card game, according to his own accounts.
"Newton's papers are among the world's most important collections in the Western scientific tradition, and are one of the library's most treasured collections," the curator of scientific collections at Cambridge University Library, Katrina Dean, said.
"Their addition to the Unesco International Memory of the World Register recognises their unquestionable international importance."
The UN Educational, Scientific and Cultural Organization's (Unesco) International Memory of the World Register supports the preservation of historically important documents and includes the Magna Carta.
Items on the register are "endorsed by the director general of Unesco, as corresponding to the selection criteria regarding world significance and outstanding universal value", according to the organisation's website.