Need advice concerning smoke/rainy conditions - It's for a book

[The Elderly Kid]

Pards,
I am commencing work on a book about a mass shooting that took place in South Texas in September, 1886. It was huge - 5 killed and many wounded, somewhere between 12 and 20 men firing at once with rifles and six-shooters. It took place in the main street of a tiny town within an area of a few dozen yards across, except for the shooting of one man after he tried to run across a vacant lot but was chased down and killed. According to newspaper reports and court testimony it was a rainy day and some were wearing slickers. I don't know if rain was actually falling at the time of the shooting or what the wind conditions were, but I am for the moment going on the assumption that the rain had stopped and it was windless.
Here's my question:  With maybe a hundred shots fired within a few seconds, under such atmospheric conditions, what would the smoke be like immediately afterward? Would it be a heavy cloud, a thin haze, mere wisps, or what? I'll appreciate any help. I'll be working on this for a long time and I've only just begun research, but I have to start somewhere.

[Springfield Slim]

The last time I shot in the rain, it was in the mid morning. The extra moisture in the air made for more smoke. It wasn't pouring, but kind of a very light rain, enough that my wife was getting too wet and cold and stopped shooting for the day. All damp mornings I has shot made for much more smoke then dry days. Sometimes the cloud just hangs there on the ground so that we have to wait,  as the next shooter was smokeless and they don't like the smoke!

[Blackpowder Burn]

I'd think it would be a dense cloud of smoke.  I know on a day with high humidity and no wind that a person shooting a 10 shot rifle string completely hides the targets so counters can't see them.  It happened to us yesterday - I was in a position that I could see the targets and 2 misses.  However, the counters couldn't see them and called him clean!  So - hundreds of rounds in a "few seconds" under those conditions equals a dense cloud.

[The Elderly Kid]

Thanks, pards, and keep 'em coming! This is pretty much what I'd expected, but I live in New Mexico and rain here is a lot rarer than gunfights.

[Mako]

Kid,

First of all you have to remember that Black Powder is relatively inefficient in converting the mixture to gas (which is what you need for a propellant).  The ignition produces about 60% solid residues and only 40% gaseous materials.

Combusted black powder residues contain, Carbon, Sulfur, Potassium Sulfate, Potassium Thiosulfate, Potassium Sulfide and Potassium Carbonate to name the elements and some of the resulting compounds.  The Potassium Nitrate in the BP mixture converts to quite a few compounds, notice they are compounds involving the Sulfur and Carbon.  Most if not all of the Sulfur compounds are very hygroscopic in nature.

When you mix gaseous particle with water droplets you get what is called an aerosol.   In other words aerosols are simply  a suspension of  liquids and remaining solid particles in a gas.  With BP smoke in a high relative humidty you have all three elements to make an aerosol.  You have the gaseous materials, the fine uncombusted particles and water.  

It has long been known that high humidity increases the aerosol mass.   For instance the "Pea Soup" fogs that London used to be known for was in fact what we call smog and was a result of the coal fire residues mixing with the moisture laden air and creating the extremely dense and extremely persistent smog that London was famous for.  I use the past tense because London's air is now much cleaner and Pea Soup fog is pretty much a thing of the past.  The last big incidents were in the '50s.  At increased relative humidity water is attracted by these hygroscopic compounds, leading to increased size of aerosol particles.  Hygroscopic materials also tend to almost emulsify with the water droplets making them very white and very dense.  This is why you see white smoke clouds with BP and different colored smoke with other  burning.

There is another factor that leads to the persistence of lingering aerosol clouds and that is the thermal caps that occur with high humidity conditions.  This actually keeps the breezes down and keeps any aerosol clouds close to the earth limiting their dissipation.  The aerosol droplets will join with other water droplets and the cloud will actually become denser until the compounds are diluted enough to make the aerosol mixtures weaker.  A lot of the aerosol will actually fall to the ground under low breeze and high humidity conditions.   They become so heavy they can't be supported by the air molecules.  In lower humidity conditions the clouds will be dissipated primarily through gas mixing with the atmosphere.

So in a nutshell the higher the relative humidity and the calmer the conditions the denser the aerosol cloud will be and the longer it will take to dissipate.

Is that what you were looking for?  That's about it for me off of the cuff.  If you need textural citations then I'd look at some articles about air pollution or even smog would be your best bets.  There are some scientific works concerning smoke and military applications.  That is how they make smoke screens, plus there is work concerning the introduction of nitrocellulose to the battlefield and the implications.  I don't think the Naval applications are as applicable, they do some interesting things to make a persistent aerosol suspension.  The Army has done quite a bit of work with armor screening aerosols especially since we are now operating a lot in low humidity environments.  That was actually always the case, many of the great tank battles of WWII were in the desert.

I can't believe  also forgot to mention Contrails.  Do some light reading on those as well.

Best of luck,
Mako

[The Elderly Kid]

Wow. Thanks. Mako. Now I know how I'll come back if anybody tells me there shouldn't have been that much smoke hanging in the air that day.
In fact, I've just found that one of the most common witness statements at the inquest was: "There was a lot of gunsmoke. I couldn't see anything."

[Shotgun Franklin]

It shouldn't be that hard for you to go to a black powder shoot of some kind. Under the conditions you describe, high humidity with no wind, the smoke can almost take your breath away. We shot yesterday under just the conditions you're talking about. The shooter couldn't see the targets, the counters were flapping their arms to clear the smoke and everyone was sucking air.

[Bishop Creek]

This is the smoke from two black powder revolvers going off at once with very low humidity, around 6%, so I can only imagine the huge amounts of smoke in the air that day in Texas.

[The Swede]

Rain is what we get a lot of here on Vancouver Island. This was a moist day.

[Noz]

Heavy smoke, virtually no visibility.

At the Old ITSASS range in Wagoner Ok, one stage was fired from a concrete "bunker" with only the target side open.

After a Frontiersman fired the stage would have to rest a "while" before it could be fired again.  Too much smoke for decent visibility. that would be one shooter, 22 rounds.

[hellgate]

If the sun is in your face without any wind you may be unable to see anything after your first shot or two. Anyone with the sun at their back would have an advantage of far less smoke glare and be able to shoot much longer at their intended target.

[The Elderly Kid]

Hellgate,
Good point. I'll have to check about the exact time of day and the orientation of the participants. The town no longer exists, but it should be fairly easy, because much of the testimony concerns a wagon that was in the middle of things, with one of the victims going "around the southeast corner of the wagon" at a crucial moment.

[Shotgun Franklin]

If it doesn't tip your hand to much, what town are you writing about?

[Pulp]

Watch this video, then write with confidence that the smoke will  hang around.



It wasn't rainy when this was filmed, but it was a very high humidity morning.

[Shotgun Franklin]

Looked like there was a slight wind from right to left. I live in South Texas, often the wind will strip feathers off of a chicken other times it's so dead still, and hot, that it's nearly hard to breath.  When it's 113, with 90% humidity and no wind dust from the cars driving down a dirt road hangs like fog.

[The Elderly Kid]

If it doesn't tip your hand to much, what town are you writing about?

It was Daileyville, about three miles from Kenedy, in Karnes County. My family is from Kenedy and I knew relatives of some of the participants when I was a small boy there in the early 50s. It was something people didn't talk about back then, and I'm only learning the details now, such as they are. All the people who knew anything firsthand or even secondhand are all dead now. I'm going to have to get back to Kenedy and go through court records, newspaper files and hopefully old family letters, if any of the old families are still around.

[Shotgun Franklin]

Very many of the shootings in the ol' days in Texas were between feuding familes. Some places are still kinda touchy about their family history.

[The Elderly Kid]

This one mainly involved the Butlers and the Elders but I believe both families have all but died out, at least in Karnes County. But there were others involved, and members of both families who had nothing to do with the enmity. As is usually the case, these things were much more complex than the clan feuding of the Scottish Highlands. Karnes is adjacent with DeWitt County, where the Sutton-Taylor feud was winding down at the same time. I need to find out if the two feuds were connected. The Sutton-Taylor business was another one the older people didn't talk about when I was a kid. There were Suttons and Taylors still in Karnes county, too.

[Shotgun Franklin]

Oh yeah, we had families 'at odds' over 'Gold Bricks' around Atascosa County. It's still don't ask don't tell about that.