Our eggs are set to auto-turn every 75 min. The incubator is also set to have a “cooling” period once daily. This is to mimic the time the hen would get off the nest and get herself some food and water.
I took 35 eggs to the 1st grade class today as well. 
Here is a picture of their incubator:
Do you see some differences? The yellow trays gently rock the eggs, rather than rolling them as my small Brinsea does. The humidity is regulated using the trough system in the bottom of the incubator. The heating element is controlled manually and the temperature gauge must be read several times a day to keep the temperature regulated.
Tomorrow we will try to candle the eggs to discern whether or not they are fertile.
The heartbeat of the chick begins in Day 3 of incubation.
The entire process goes from a single cell embryo to a fully feathered chick in a mere 21 days.
That’s pretty impressive!
Dr Vet Sonya 