▁ 1 9 2 9 . ▁" The ▁Col lo idal ▁Men ace ", ▁Ama zing ▁St ories , ▁December ▁ 1 9 2 9 . ▁" Old ▁C rom pton ' s ▁Secret ", ▁Ast ounding ▁St ories ▁of ▁Super - S cience , ▁February ▁ 1 9 3 0 . ▁Re print ed ▁in ▁Har l ▁Vincent ▁Res ur rect ed . ▁" Before ▁the ▁Ast ero ids ", ▁Science ▁Wonder ▁St ories , ▁March ▁ 1 9 3 0 . ▁" The ▁T error ▁of ▁Air - Level ▁Six ", ▁Ast ounding ▁St ories ▁of ▁Super - S cience , ▁July ▁ 1 9 3 0 . ▁Re print ed ▁in ▁Har l ▁Vincent ▁Res ur rect ed . ▁" Sil ver ▁D ome ", ▁Ast ounding ▁St ories ▁of ▁Super - S cience , ▁August ▁ 1 9 3 0 . ▁Re print ed ▁in ▁Har l ▁Vincent ▁Res ur rect ed . ▁" Free ▁Energy ", ▁Ama zing ▁St ories , ▁September ▁ 1 9 3 0 . ▁" T anks ▁Under ▁the ▁Sea ", ▁Ama zing ▁St ories , ▁January ▁ 1 9 3 1 . ▁" T errors ▁Un seen ", ▁Ast ounding ▁St ories , ▁March ▁ 1 9 3 1 . ▁Re print ed ▁in ▁Har l ▁Vincent ▁Res ur rect ed . ▁" In visible ▁Sh ips ", ▁Ama zing ▁St ories ▁Qu arter ly , ▁Spring ▁ 1 9 3 1 . ▁" To o ▁Many ▁Bo ards ", ▁Ama zing ▁St