Ken Slater

semiprozine n.	1953 K. F. Slater Index to Advertisers in Operation Fantast Handbook 1953 64 FANTASTIC WORLDS…(semi-prozine).
space epic n.	1957 K. F. Slater Something to Read in Nebula Science Fiction (#25) Oct. 105/1 Charles Eric Maine’s High Vacuum…. As the title suggests, the story is a ‘space’ epic, the first manned moon trip.
time opera n.	1948 N. Lindsay & K. Slater Among the Magazines in Fantasy Review Aug.–Sept. 19/2 Emmett McDowell’s ‘Citadel of the Green Death’ is fast-action space opera of the sort beloved by Planet fans; ‘Valkyrie from the Void’ a Basil Wells ‘novelet of stellar savagery’ is more in the Tarzan tradition, and James Blish’s ‘Against the Stone Beasts’ is a time-travel tale of war between a winged race and creatures of negative matter—you might call it time-opera.