|cracked egg at 90 hours incubation|
I'll keep candling daily, I think, and if/when something quits, everything will line up nicely. I have to admit that I'm kind of hoping all eight hatch though.
Here's a bottom view of the cracked egg. The crack is at the bottom (fat part) of the egg. It's not too bad of a crack, but because of the location, I was worried about sealing it up with wax, or nail polish, or elmer's glue, which is the normal fix when an egg cracks. Generally speaking, it's not a great idea to set cracked eggs. Those fixes are intended for candling/hen mishaps that happen during incubation. You can see the weakened spots because the light goes through the egg very easily.
As a side note, if you are wondering how I candle, I have a tutorial on how it works here. Photographs were taken with my iPhone 4.