The eight brushes given by Bacon to fellow artist Clive Barker in 1978 are in a paint-splattered butter bean tin inside a clear box. They have an estimated price of 20,000 pounds to 25,000 pounds.
Bacon's paintings have sold for as much as USD 86 million at auction.
Also among the 150 lots in Christie's Out of the Ordinary sale: a rocking horse as tall as a house; a flying machine from Steven Spielberg's "Young Sherlock Holmes"; a stuffed ostrich; and a Triceratops skull valued at between 150,000 pounds and 250,000 pounds.