Benson Herbert

parallel world n.	1931 B. Herbert World Within in Wonder Stories Aug. 313/1 The disconcerting change of direction of gravity, catching him unawares while passing along the fourth dimension from that tri-dimensional parallel world so near to ours, together with the sudden enormous increase of his weight, proved too much for his weakened condition.
rocketeer n.	1935 B. Herbert Perfect World in Wonder Stories Oct. 522/1 On the desk there was a copy of The Weekly Rocketeer, yesterday’s issue. It was a trade magazine, cost one and a half marks, and was full of advertisements for soarers, metal hulls, rocket-tubes, external-combustion engines, fuel mixtures, and so on.