Philsp.com source (it would be hard to guess).
From Pulpartists.com :
“In 1928 he sold interior story illustrations to Street & Smith for Clues. They paid $2 for each one-page drawing. He also sold freelance pulp covers to Air Adventures, The Danger Trail, and Wide World Adventures”.
That was just before his sci-fi illustrations :
“His first science fiction illustrations were sold to Amazing Stories in 1929”
Prohibition art by Hans W. Wessolowski.
Philsp.com source (it would be hard to guess).
From Pulpartists.com :
“In 1928 he sold interior story illustrations to Street & Smith for Clues. They paid $2 for each one-page drawing. He also sold freelance pulp covers to Air Adventures, The Danger Trail, and Wide World Adventures”.
That was just before his sci-fi illustrations :
“His first science fiction illustrations were sold to Amazing Stories in 1929”