The two sides of inventor Barnes Wallis have been revealed in a document which has just come to light.
It shows he was studying guided missiles during World War Two, after working on the bouncing bomb used in the Dambusters’ Raid.
But on the back, there is a note from his wife, referring to the Ripley-born scientist scoffing a cake sent by friends. The card sold for £240 at an autograph auction.
Nottingham auctioneer Richard Davie, who organised the sale, said: “It is an interesting and unusual document.”
Written in blue ink, Wallis made a chart to compare the advantages of missiles with or without wings. He broke it down into categories to consider their speed, acceleration, range and the height they would fly. He appears to come down in favour of winged missiles, saying their speed and acceleration would be “very good” but suggesting wingless models would be able to fly higher. When enthusiasts turned over the paper, they found a message from his wife written 34 years later in which she says: “Excuse my paper. I am very conservation minded & I hate wasting my husband’s ‘backs.’ The cake was much enjoyed by Barnes. As to the tea, it is heavenly. I expect to see you both at 12.30 off the 12.2 from Waterloo. I have a small present for you. Arthur Whitmarsh & his wife came on Thursday, asking for Barnes’s autograph. We had never met him & knew nothing of him till he rang up to ask if he could come. . .we liked him very much.”