Discussion on the papers - Reflection curves and propagation characteristics of radio waves along the Earth's surface - by Dr. McPetrie and Miss Stickland, An experimental investigation of the propagation of radiation having wavelengths of 2 and 3 metres, by Dr. McPetrie and Mr. Saxton, and Radio direction-finding on wavelengths between 2 and 3 metres (100 to 150 Mc/s), by Dr. Smith-Rose and Dr. Hopkins, before the Wireless Section, 3rd April, 1940