From Lustige Blätter 1919.
Funny papers was the title of a German-language satire magazine. After a brief start-up phase in Hamburg, the magazine was published as a weekly newspaper from 1886 to 1944 in Berlin. It was founded and published by the writer Alexander Moszkowski.
[Image found here. Note that there is no Wikipedia entry for Lustige Blätter in English.]
From Electrical Experimenter magazine, December 1919:
“In the circus we are used to seeing a person “loop-the-loop” or turn a somersault in mid-air while in an automobile, the vehicle and its passengers landing right side up on a properly inclined platform, down which it glides to earth. Our artillery experts can compute with extreme accuracy the trajectory of various projectiles, both large and small, and thus it should be quite possible, with the aid of modern mechanical engineering technique, to build one of these aerial passenger rocket amusements successfully. The gun out of which is the shell or rocket, with its human cargo is shot, may be operated by compressed air, by powder, or it may be an electromagnetic gun.”
[Found here. Click the link above for .pdf of the issue.]