As we say goodbye to one of our friends, here is a parting look at a portion of Greenhouse 1. This wheel turned a gear, which in turn moved a chain, which turned another gear at the roof line. That gear turned a series of arms on a pipe to lift a portion of the roof to allow excess heat to escape from the peak on the hottest Summer days. Every morning one of the first steps is to crank open the roof and let the air vent out, and one of the last steps of the day is to seal it up again to retain heat on cool spring and early summer nights. After many decades of service an electric fan was added to this house to give a little oomph to the air moving through, but this classic piece of the farm still achieved a lot of cooling via passive air venting. In fact the technology of the passive vent is still so modern that it is the only method of venting we employ in our new state of the art glass house, though those roof vents are opened and closed by toothed arms and gears and computerized motors.