Unfortunately, all the info from the 30's and 40's is still being posted on the web. Back in the day, most incubators were heated with kerosene lamps. This is why all the literature has 80% humidity as the norm for hatching eggs. Kerosene heat tends to drive the moisture out of the bator.It's 65 in my room already so I will try not adding any water at all. I read up to 80%humidity for hatching but realise that's a bit silly now.