On 12 February 1935, Watson-Watt sent the secret memo of the proposed system to the Air Ministry, "Detection and location of aircraft by radio methods". Although not as exciting as a death-ray, the concept clearly had potential, but the Air Ministry, before giving funding, asked for a demonstration proving that radio waves could be reflected by an aircraft. This was ready by 26 February and consisted of two receiving antennae located about away from one of the BBC's shortwave broadcast stations at Daventry. The two antennae were phased such that signals travelling directly from the station cancelled themselves out, but signals arriving from other angles were admitted, thereby deflecting the trace on a CRT indicator (passive radar). Such was the secrecy of this test that only three people witnessed it: Watson-Watt, his colleague Arnold Wilkins, and a single member of the committee, A. P. Rowe. The demonstration was a success for, on several occasions, a clear signal was seen from a Handley Page Heyford bomber being flown around the site. The Prime Minister, Stanley Baldwin, was kept quietly informed of radar's progress. On 2 April 1935, Watson-Watt received a patent on a radio device for detecting and locating an aircraft.