The Stride Reckoner
Estimate a stranger's height from their walking stride — the method Holmes uses at Lauriston Gardens.
In A Study in Scarlet Holmes announces the murderer's height from the length of his stride. The rule of thumb he relied on: a natural walking stride runs to roughly 0.415 of a person's height. Measure a stride in the mud (or on the beach) and reckon the walker.
Drawn from A Study in Scarlet (The Four Novels, 1887) — read the summary & analysis, or try The Lauriston Gardens Room, this story's game. More at the Game Room and the tool bench.