Card of authority to use portable receiver, issued by the General Post Office, British, 1922. Issued on April 13 1922 to the Hon. E H Cozens-Hardy, of Letheringsett Hall, Holt, Norfolk. The card reads 'The bearer, the Hon E H Cozens-Hardy of Letheringsett Hall, Holt, Norfolk, has been authorised by the Postmaster General to conduct experiments with portable wireless receiving apparatus within a radius of ten miles of (1) Messrs Pilkington Bros Works, St Helens, (2) Letheringsett Hall, Holt, Norfolk (but not within one mile of any Government wireless station)