Well today, I candled the eggs in the incubator that I had found the light bulb burned out on Sun (eggs cold, temp a 74*). There are a few survivors and mostly from the older set eggs that are due to hatch on the 17th. Most of my losses were in my later set eggs that were due to hatch on the 25th. The larger "chicks" must have been able to retain heat a little better that the younger ones in the eggs.Hoping I get some to hatch. Guessing they will be late because of the incident. Go chickies!
Sounds about right. The older eggs had larger embryos. When they start to get larger they get the ability to regulate their own body heat so it's possible for them to survive despite a period of cooling. There was an article a read on this somewhere if i can dig it up I can link it..