This gem was mentioned in Henry Petroski’s “Small Things Considered: Why There Is No Perfect Design“.

In 1662 William Grey of Pittendrum built a house for himself in Edinburgh (pictured above). He was concerned about the problem of burglary and intruders entering his house while he slept, so he came up with a devious solution: he designed his staircase to have uneven steps. While he was able to learn the pattern, any night-time intruders would stumble on them, causing a noise. This would wake him and presumably elicit a loud stream of Scottish expletives. This response would then cause the intruder to flee, which, as the final part of his design, would cause them to stumble again but this time fall down the entire flight of stairs. Problem solved!

In the book ‘Small Things Considered’, Petroski then goes on to discuss the dangers of staircase design (5000 people a year are killed in the US by falling down stairs), the ergonomics of staircase usage (descending stairs is harder than ascending on steps with overhangs, due to the shape of our feet), cultural differences in the people wear out wide staircases (Americans prefer the right and taking inside corners because they drive on the right), and the ancient Greek specifications for staircase design in temples. To get an idea of what the rest of Petroski’s book is like, picture this sort of meandering but logical analysis proceeding through all kinds of things from cups to luggage, glasses, supermarket floorplans, toothbrushes, paper bags and non-stick pans… that’s basically his book in a nutshell. Not everybody’s ideal bedtime reading, but a really pleasant book to flick through from time to time.