A book is a book is a book. But some are better than others.
It’s what policemen did when a suspect was getting away in 1950s Paris. So the incident in Simenon’s Maigret and the Man on the Bench. He wanted to alert other cops in the neighborhood.
Whistles all had same sound, I’m sure, so blowing it was just to get them looking for a running man or woman. Didn’t work this time in this 1953 book, 2/3 through it. Man got away.
Now excuse me, I have to get back at it. The book, that is.