Thanks to Ruth McNair and Ron Kean for their help in identifying the photo at left, which was posted in eCALS two weeks back. They agree that it’s an old-style Petersime incubator.
“The buttons along the top probably rotated the cartons of eggs because incubating eggs need to be turned regularly,” says McNair, an editor at the Center for Integrated Agricultural Systems. “The Poultry Science Department on the UW Madison campus used to hatch out chicks and when the staff were done with them, or had extras, they sold them. I think my father bought chicks from them.”
The trays at the bottom were for hatching, adds Kean, an Extension poultry specialist. “Typically, the eggs are taken out of the turning mechanism for the last three days of incubation. They would have been moved to the bottom trays at this time.”