norman marsh's career as a cartoonist began c. 1922. he created the hardboiled detective character dan dunn in the proto-comic book "detective dan: secret operative no. 48" (may 12, 1933). the book contained all-original stories as opposed to reprinted newspaper strips. comics historian don markstein notes that this periodical and the only two others from this publisher were pioneering in that they contained "non-reprinted comics in 1933", though these periodicals were not "in modern comic book format. theirs were done as tabloids" with "detective dan: secret operative no. 48" measuring either 9 1/2 x 12-inches or 10 x 13-inches (sources differ), with black-and-white newsprint pages and a three-color cardboard cover.