Centaur Publications (1938-1942) was one of the earliest comic book publishers, with earlier incarnations Comics Magazine Company (1936), Chesler Publications (1937), and Ultem Publishing (1937). Before Centaur went belly-up (mainly due to poor distribution), they published 21 different titles -- not including several title changes.
One other factor that may have led to Centaur's demise might have been a supreme math ineptitude. Well, that's my theory, based on how they numbered their titles because for the life of me I can't figure out any sane for Centaur to do what they did with Keen Detective Funnies. Series 1 ran from July to December 1938 and were numbered #8 to #11. Then Series 2 ran for twelve monthly issues in 1939, numbered #1 to #12. Series 3 began in January 1940 with issue #1, then ran from March to September 1940, with the issues numbered #18 to #24. You do the math -- I can't. It does add up to 24 issues, but why they did it that way is beyond my comprehension.*
This is a jam-packed issue. Sixty-eight pages, although only sixty-four were able to be posted on the link. Here is the original adventure of Air Man, plus stories of ventriloquist and scientific detective Dean Denton, radio newshawk Spark O'Leary, Bay City district attorney Dean Masters, super-sleuth The Masked Marvel, The Eye (a large disembodied eyeball that is "the symbol of man's inner conscience"), and FBI agent Dan Dennis. Some of these name may be familiar because after the characters fell into public domain, they were picked up by other publishers.
*None of what I described in the this paragraph has anything to do with the contents of the August issue linked in this post. I mentioned it only because I get easily distrac -- Look! A squirrel!