Where did the term catching some z's come from?

Answer 1

American cartoon comics have a long tradition of using a Z or Z's to denote snoring or sleeping (http://en.wikipedia.org/wiki/Speech_balloon) . From this comes the phrase "catching some z's" meaning to get some sleep.

This begs the question, "how did z's come to represent sleep in comics?". I haven't found any research to answer that, but my own supposition is that it derives from the sound of snoring with it's regular coarse vibration inspiring the common metaphor of "sawing logs" in ones sleep. The 'Z' represent the tooth pattern of a saw or the saw-tooth sound wave corresponding to the sound of snoring.

-John Alvarado