Playgrounds used to be a child's first experience with Darwinian Selection. The play yard was full of steel pipes and hard wood, all set to give the agile fun and the inept child anything from scrapes and mild concussions to dizziness and stomach-emptying nausea. But you know, you survive and learn. The equipment that terrified you as a first grader is a welcome challenge when you're a fifth grader. And a welcome bit of nostalgia in middle age. The top item was a simple construction of steel plumbing pipe. You could clamber all over the thing. You could play "Monkey Tag." If you were agile and strong, you could get all the way to the top. And if you were a daredevil, you could grab onto one of the center bars and slide the terrifying seven feet down to the ground. The carousels showed two design philosophies. The all-metal one was easier to use. The pusher could grab those big upright rails and propel the riders to nausea-inducing RPMs. And if they were quick enough, they could swing onto the carousel and enjoy the ride themselves. The lower carousel came in two versions. The version I grew up with had only the green outer ring for seating. Kids sat with their legs on the inside, holding onto the iron bar as the pusher propelled the ride. Other riders might sit facing outward, clutching the bar behind them to avoid a quick centrifugal flight to the gravel spinning below. The second version show here features a center area was filled in with planks that let riders sit safely within the bars. BUT those on the outside were now facing outward and risking that centrifugal launch. In either version the riders' outstretched legs made it difficult for the pusher to grab those six small bars. The metal carousel was found in a small park in Pewaukee, Wisconsin. The other two pieces were found in a forgotten corner of a lakeside park in Mequon, Wisconsin.