Four marbles used by inventor Sir Barnes Wallis to develop the bouncing bombs for the Dambusters raid are to be auctioned for £600. The marbles were borrowed from his young daughter for experiments in the garden of the family home in Effingham, Surrey, using a tin bath filled with water.
The 1943 raid on Germany's Ruhr valley, carried out by 617 Squadron flying Lancaster bombers at just 60ft and 240mph, targeted dams vital to German arms production. The simple tests helped design the iconic bouncing bombs that changed the course of the Second World War.
The auction, taking place on Tuesday in Towcester, Northants, also includes a wooden sight from a 617 Squadron Lancaster that flew on the raids, a map light, and a navigator's parallelogram used to guide the bombs to their targets.
Last week, the family of Flight Lieutenant Richard Trevor-Roper, a rear gunner in Guy Gibson's lead plane, announced they would sell his gallantry medals for £60,000 after discovering them in a box.
