Back in 1890, a certain courier made pick-ups and deliveries
in a certain section of Brooklyn. Every day, he would ride the streetcars
that ran four times per hour along DeKalb Avenue between Flatbush
In those days, two overlapping trolley services operated
on the DeKalb tracks, which branched both north and south onto the Flatbush
Line. Every other car heading either south to Prospect Park or north
to the newly opened Brooklyn Bridge.
The courier always disembarked before Flatbush. Over
a period of many weeks, he noticed something strange: Though he boarded
the streetcars completely at random, he would find himself riding on a
Brooklyn Bridge car twice as often as one running to Prospect Park.