...do shadows on a sundial in the southern hemisphere march "clockwise?" (don't quibble, you know what I mean)

No, assuming I know what you mean.

Clarification: "clockwise" = looking at a circle from above, starting at the top and moving to the right around it

Which means that if "clockwise" is defined from sundial-shadow motion, it's linguistic-based evidence that clocks were invented (read "modern civilization arose") in the northern hemisphere. Yes?