Holmes and Bicycle Tracks
One of my favourite little moments in The Priory School is Holmes examining bicycle tracks and identifying the type of bicycle from the marks left behind.
It’s easy to forget just how new this sort of detective work would have seemed to contemporary readers. Holmes is effectively doing forensic analysis of tyre tracks, long before this became routine police work.
And, naturally, he can tell far more from a bicycle track than most of us could tell from the bicycle itself.
It does make you wonder what Holmes would make of modern forensic science. Probably complain that everyone has made deduction unnecessarily complicated.