Ryle M., Smith F.G., Elsmore B. A Preliminary Survey of the Radio Stars in the Northern Hemisphere, MNRAS, 110, 508-523 (1950).

Smith, F. Graham (1923-) Astronomer who joined Martin Ryle's radio group in 1946. He observed Cygnus A using a Michelson interferometer Eric Weisstein's World of Physics at 80 MHz. He also built the Long Michelson Interferometer at the Old Rifle Range in Cambridge in 1950. This device operated at a wavelength of 3.7 meter, and was operated using Ryle's phase switching technique to compile the 1C survey in 1950. He also used the interferometer to measure the electron Eric Weisstein's World of Physics density in the ionosphere Eric Weisstein's World of Astronomy (c.f., Evans). In 1977, his book Pulsars was published (Sullivan 1984, p. 413). 

I have updated the 1C page accordingly.