Inspired by this thread, I’m wondering about police whistles.
In old b&w films set in the pre-radio era, you often see the scene where the lone policeman comes across the body or crime scene and blows his whistle to attract the attention of nearby colleagues. I’m thinking here a foggy scene probably in old London town. Within seconds, several policemen will be on the scene.
My question is, is this realistic? Would there be that many policemen within earshot to come running that quickly?
They’re kind of like moderator whistles. You know, one of us blows the whistle, and we all come running…
Okay, seriously, though. In the days when most cops walked a beat rather than driving or riding, dense areas often did have cops walking their beats within just a few blocks of each other. Those police whistles are LOUD! They certainly could hear them from blocks away and other cops could be there within minutes. I’m not so sure about “seconds,” but I suppose it’s possible.
I also believe there was a code to the whistle.
The pre-radio era was also mostly pre-motor vehicles and electrical machinery. Even a large city would be very quiet by modern standards, more like a small town or village is today.
So the whistle would carry a lot farther in 1880s London than it does in 2009 London suburbs even.
Are you sure that the place would be that quiet? I was walking through our town’s market place the other Sunday morning when there were a couple of police horses taking place in a small commemorative parade. The sound of just those two horses on the cobble-stones of the market place was surprisingly loud. In the 1880’s there were thousands of horses on the streets of London, both day and night. That would have created a tremendous din. On top of that you would have had the iron tyres of carts and carriages adding to the general noise.
Plus you got the screaming of all those prostitutes getting ripped…
I would also suspect that there was a greater number of people on the street hawking goods. If you go to modern day Japan, for instance, where bipedal transportation is still the norm, trying to get the attention of people on the sidewalk is a fairly big deal and hence there’s a lot of noise from the shops trying to attract your attention.
But I suspect that tall buildings would be more likely to block out a loud whistle than a regular street din. Without that sort of blanket, I wouldn’t be surprised if the sound traveled well. And of course, most likely most streets would be quite quiet. Most commerce happens along a single courseway, leaving surrounding streets quiet and largely empty.
Besides whistles, they also used rattles, or signaled each other with their clubs, as seen at 6:50 of this part of Buster Keaton’s cops.
Why the focus on the 19th century? My dad still has his whistle issued to him (by the Lancashire Constabulary) in the late 1960s, similar to the one on the right in this picture. By the 1960s, the din (or lack thereof) of horses hooves and street vendors had become irrelevant, yet they were still being issued.
You whistled? 
Beat cops did back each other up, and when one whistled, the cops who heard him whistled too, and ran towards the first whistler. Remember, too, that there were quite a few traffic cops around, directing traffic, as well as the beat cops, so those men (and in those days, they were all men) could also respond.
I used to have an emergency whistle when I was in Camp Fire Girls. I used to love to go camping, and I also loved to wander off on my own, which was very much against the rules. An emergency whistle is surprisingly loud, and can carry for quite a distance.
I recently saw a Discovery Channel episode of “How it’s made” that showed UK police whistles being manufactured, so I’m assuming they’re still issued, though I can’t find any evidence to back this up using google.
Back in the 19th Century that’s how our town’s fire department worked. If one of the firemen spotted a fire, he’d start blowing his whistle. That would be picked up by nearby firemen, who would blow their whistles, until the sound rached the fire station. The people at the station would then ring the fire bell, which would start another round of people whistling until eventually all the firemen got to the fire house, and then went to the fire.
