First day cover: 'British Discovery', featuring television (Baird), penicillin (Fleming), radar (Watson-Watt) and the jet engine (Whittle). Envelope contains card bearing details of the stamps and the discoveries issued by the GPO, 1967
First day cover: 'British Discovery', featuring television (Baird), penicillin (Fleming), radar (Watson-Watt) and the jet engine (Whittle). Envelope contains card bearing details of the stamps and the discoveries issued by the GPO, 1967