Weird places to split an encyclopedia

I'm sure they do it just by page count, but some of these make me wonder if the editors weren't having a little fun:

Say it real fast, it sounds like 'ménage-à-trois'

Well, they do have the highest per-capita murder rate..

"Ooh, what lovely little Edisons you have around the tree"

We could use a little more of this..

Cylinders, perhaps?

I don't think they had those...

The avowed enemies of the Zoroastrian Alliance, I'm sure