Papers of John Guy Porter

A copy of Porter's script for 'The Night Sky in July' on Comet Mrkos (1955), observations with field glasses and the composition of this Comet's tail; the Milky Way in the southern sky, Vega, Cygnus, Aquila and Altair, Saturn in Sagittarius and the centre of our galaxy; the shape and size of the galaxy; the Sun's position in the spiral arms, rotating about the galactic centre; the cases of other stars not sharing in this general motion, speculation on the nature of the galactic centre, and comparisons made with the Andromeda Nebula, showing many more non-uniform stars near its centre with no dust, the observations being carried out by infra-red and radio receivers; and the recent survey of intense radio sources at Cambridge showing some sources with invisible counterparts, the apparent non-proportionality of the fall off in power of the sources, and the distance of the sources providing a test to theories of the origin of the universe.