You’ll need more than a glance to take in, and fully appreciate, the mural being created on the south-facing wall of the old Skyplex Building on Bridge Street in Springfield. You’ll probably need at least 10 minutes to fully absorb all the images on the 100-foot-long wall. There are dozens of them, large and small. But you’ll also need a cheat sheet of sorts (a few different ones will be created — more on that later) and probably easy access to Wikipedia. That’s because, while some of the people can be easily identified (Muhammad Ali, Abraham Lincoln, and even Peter L. Picknelly, among them), most of them are far more obscure and need some explaining, at least when it comes to their connection to, and importance to, the City of Homes.