Someone already knows the answer to this, (but not me): if you examine a statistically representative set of ancient books, (both pre- and post- Gutenberg) wha

Someone already knows the answer to this, (but not me): if you examine a statistically representative set of ancient books, (both pre- and post- Gutenberg) what is the average line length? And doesn't that partially depend on "standard" parchment/vellum size? And doesn't that depend on the size of a young sheep's belly? ("The tyranny of the size of sheep!" Where's James Burke when you need him?)