Well, next time I'm near the pharmacy hopefully I'll remember to pick up a couple more glass thermometers.
This morning I noticed the broody hen was off the eggs--first lengthy stretch in a week. So I figured I'd take a look at the eggs while she was off. I started looking at the eggs and they all seem to be developing fine except 1 and it was clear! I couldn't figure out how it was clear when there had been veining before. It was a dark egg so I wondered if I just couldn't see in it well enough in the lighter environment of morning. I looked at the others and tried again, nothing. So I looked at the end for markings to see which it was...nothing.
It's a fresh marans egg! When the hen got off to stretch her legs the marans hen laid an egg. It looks just like the welsummer egg in there. Duh, put in 4 and there were 5. Good thing they're marked!