From therethere.com, a bit about one of the contributions of Baltimore's rowhouses to urban culture: "Imagine this: it's a sweltering mid-Atlantic summer afternoon, back before the days of air conditioning. You need the windows open for some fresh air, but you don't want your neighbors peeking in to see your pit stains. Back in the early 1900s, a local shop owner came up with a clever solution to this problem: screen painting. He covered his window screens with images of his wares, wiping away the excess paint to make sure they still let the breeze in. The practice became a sensation — people liked being able to look out on their block without being spied on by their neighbors. At one point, over 100,000 of the city's homes had scenery painted on their windows. These days, the screens are recognized as folk art — local groups are uniting to preserve the tradition, and the American Visionary Art Museum even hosted a 'Rowhouse Rembrandts' exhibit to show off the city's best screens. Leave it to Charm City to beat the heat by turning every block into an outdoor art walk." Full post here. I think the desire for privacy in dense townhouse neighborhoods was probably also a large contributor to the Belgian mastery of lace, which they used as curtains in first floor windows. Necessity is the mother of both invention and art.