"Can I choose waterboarding instead?"
I read that the Clock is considered the first masked character to appear in comic books. There were costumed and disguised characters in the pulps; the Shadow and Zorro spring to mind, but apparently before the Clock there weren't any characters in comic books who wore masks.
Well, how 'bout that for trivia?
I can't say a lot about the Clock's mask, though, since it is just a piece of black cloth with an odd little flounce at the bottom. It doesn't look like it would inspire terror in any criminals.
This story is from Feature Comics #26, November 1939. The drawing, by Clock creator George Brenner, is 1930s-styled comic book artwork: static figures, strict eight panel pages. The story is straightforward: The Clock is being framed and he goes right at the villain. The coloring, as in a lot of old comics from the Quality Comics line, is primary, and leads to interesting color choices, like a bright red car with yellow fenders. The colorist, obviously blinded by his or her colors, has completely screwed up the coloring in the last three panels, where Captain Kane and Fingers Holts switch colors, and then Captain Kane's suit changes again in the last panel to bright green.
There's one bit that struck me when the Clock threatens Fingers to make him confess. He tells him he's starved a rat, and what if he puts the rat on Fingers' belly under a metal bowl, and then heats the bowl? The rat can't chew the bowl to get out, so what does he chew? Bwooowaaahahahaa. Don't show this to the CIA. They might drop waterboarding in favor of this tasty torture.