I've been meaning to ask this for sometime, and I guess this is the time. Not that I currently plan on hatching my own, but I'm just curious. A few months ago I was watching a series on farming in Victorian and Edwardian times and the researchers were living and working, as much a possible exactly as folks did in that time period. Same housing, same tools, everything. One of the things that really grabbed my attention was their incubator. It was made of wood and consisted, as far as I could see of two drawers. A larger one for the eggs and a smaller one that held a candle. As far as I could see there wasn't even a thermometer and they got a good hatch. That begs the question are temperatures really that critical? Unfortunately, both series have been removed because of copyright laws.