TechStuff On Fire

because here's the thing. We wanted to look into camping gear and we did, and as we were doing it, we saw all these cool things about different fire starting technology and and we thought, you know, it would be kind of cool to talk about this. But the more we saw, the more we thought, well, this is just going to completely dominate this episode. This could in fact be a whole episode. And then wait a minute, we have the full power to make it an entire episode.

So that's what we're going to do. So first of all, we should mention that fire obviously one of the most important discoveries that that early humans made. It's a pretty critical technology to human existence. Yeah, you could argue that because it's technically part of a chemical reaction, maybe you don't call it a technology, but it plays an integral role in so much of our tech, uh and and certainly the technology that we used to create it. Yeah,

I mean that's technology, it's technological. So we're going to cover everything from low tech ways of making fire to some pretty uh pretty high tech and uh terrifying obviously ways to make fire. So we've spent a lot of human history, not we personally humans, as a general rule, it's spent a lot of history learning of different ways to make fire, to control fire, to extinguish fire. We've had full episodes on firefighting technologies in the past. But

what is fire? So this is part of that chemical reaction I was talking about. It's essentially a chemical reaction between oxygen and some sort of fuel source has reached it's ignition temperature a k a. The temperature at which it will burn. Right, So when a substance, whatever it may be, has reached that temperature, if it is in the presence of oxygen, it will burn and thus we get fire. Now, flames from a fire keep the fuel

at its ignition temperature. That means the reaction becomes self sustaining as long as you have fuel, which is you know, that that that's the dangerous thing about fire, right, This is a chemical reaction that's just going to continue until all the fuel is gone, or you have otherwise found a way to extinguish it, perhaps by removing the oxygen from the environment or dampening it with something. Yeah, so which lowers the temperature as well. Yeah. So this this

is the obviously the very dangerous part about fires. That you want to make sure that you have a controlled environment where you can control exactly how much fuel is being added to the fire to make sure you don't have a nasty situation pop up. Though. You mentioned ignition temperature, and technically any given fuel has two a friend technician temperature,

that's true, there's the piloted ignition temperature. That's how hot a fuel needs to be before it will catch fire in the presence of a spark, so it doesn't have to be as hot as if if you don't have any sparks there. For an object to burst into flame in the presence of oxygen, it's temperature has to be much higher. That's the unpiloted ignition temperature. Right, that's kind of the spontaneous combustion s Yeah, exactly, except that means

a different thing, but but similar similar, right. So, for instance, if you were to heat up a piece of wood to a certain temperature and then hit it with a spark, it'll start to catch fire. You would have to heat it to a much higher temperature for it to just start burning it to itself. Yeah, So that that's one thing we should point out now. Granted we're gonna mostly be talking about piloted ignition temperatures because we're talking about helping things along by adding a little spark to it.

And also something to remember, the fuel that has a large surface area to volume ratio burns more readily, meaning that you've got a lot of surface area and you don't have a lot of volume, you can heat up and get to that ignition temperature much faster than if you had a lot of bulk to you because that temperature could then be conducted away from the point of heat, and it takes longer for you to actually get that to catch fire. Also, as a fuel source itself, it's

going to have more exposure to oxygen, yes, exactly. So you know, one of the many reasons why you want to use little bits of tinder before throwing logs onto a fire. I mean, it's the tinder is going to catch fire more easily and then you can start to build up from there. So going very very basic one is the most basic way early humans, uh interacted with fire, finding some fire and then using it for stuff. Right, So this isn't so much making it. This is what

is that big hot orange thing over there? Let's go check it out. I bet we can do something with that. And the thing is is that there's evidence that preda humans were deliberately controlling this natural found fire to do work for them as long as one point five million years ago. Right, So once you figure out, oh this fire eats stuff, if we keep produces heat, yeah, if we keep feeding it, it will stay around. If we stop feeding it, then it could go out and we

can kind of bring it over here if we want to. Yeah, yeah, we have to be real careful about that. But yeah, this, this is this is all before we had found ways to necessarily make it ourselves. It was just taking advantage of something that was found, you know. And of course fires happened in nature for multiple reasons. But if we wanted to make it ourselves. In fact, this is something that we can still do This is what early humans did, and if you're really determined and you are patient, you

can do it too. People still do it today. You can make fire through friction. So first we gotta talk about friction. Friction is the resistance to the relative motion of two solid objects that are in contact with one another. So in other words, like if uh, we have a table here in front of us, I have my hand

on the table. If I want to slide my hand across the table, first I have to put enough force to overcome this resistance to the motion, this friction, and even then I'm going to feel the friction as my hand moves across the table. That Now, the actual amount of friction is usually proportional to the force pressing the surfaces of the two objects together. So if I'm pressing down really hard on the table and then try to move my hand, I'm going to encounter more friction than

if I just very lightly had my hand on the table. Obviously, friction can be things that are you know, an object that's just on a flat surface that's not moving at all, and maybe it's an inclined surface, and the the the normal force, the force that's pressing the surfaces together would just be gravity in that case. But you can also have two different objects that are experiencing friction against each other that aren't. You know, gravity is not the main

force at play. That's also totally possible. Um. So the roughness of the surfaces also affects the amount of resistance that they have to moving against each other. That makes sense, right, If you're using a rough sand paper against some wood, then it ends up feeling. You can feel that resistance and you can feel the heat certainly using that a little bit. If you use a really finely grained piece

of sand paper, the resistance isn't as much. You're you're going to be able to move that paper a little more easily. Interestingly enough, this only is true to a point, right. This this is relatively simplified, because if you, as it turns out, okay, if you take two perfectly smooth sheets of metal, yes like flawlessly smooth, and you put them in a vacuum, right, and you try to rub them against each other. They had here, they had here, it's

called cold welding. They actually, on a molecular level, adhere to one another. So at this point you would think normally, if you if you're talking about perfectly smooth surfaces, you would think friction lists. You would think, oh, well, those things are just going to slide right off each other, but actually the opposite is true. They will cold weld together on a molecular level. So we just keep that in mind that when we're talking about friction, we are

simplifying things. We're using a very kind of macro look at it. There's also the coefficient of friction. That's essentially the amount of resistance that you have, that ratio of the frictional resistance force to that normal force pressing together the two services. So you're moving one object against another object, and some of that energy you put into moving the object goes to overcoming that friction, and that energy is not lost because you don't lose energy. Yeah, you don't

create or destroy it, you just converted. It's converted into heat. Yes, So whatever heat, whatever energy would have been used overcoming that friction gets converted into heat. So when you rub two sticks together, those contacting surfaces start to heat up, and if you rub them together fast enough and for long enough, the dust or charred that's given off by those sticks will grow hot enough to glow and that

becomes your coal. So the coal in this case, it's not coal like you would dig out of the ground. We're talking about an ember, something that is so hot that it may be glowing, giving off light as well as heat. And then you would introduce that coal to tender too in order to to get a flame going.

And you can do this with sticks, although more frequently you'll have something like a board and a stick and you'll do a like a hand drill, so that you drill a stick against the board and you start boring a hole and as a as a result, the dust that's around the hole will get hot, and if it

gets hot enough, it becomes a coal. Or you might have a piece of hardwood that's like a rod and some soft wood that has a little trough dug in it, and you just rub the end of the rod through the trough rapidly, and that also will generate this very hot char that eventually we'll get hot enough for it to become a coal and then you can light a fire. Yeah, it sounds like it's really easy. This is not something

that's necessarily easy. It actually takes quite a bit of practice. Usually, I mean people who try it for the first time are rarely successful unless they have the careful guidance of an expert who has done it before, because you know it's it's It can be exhausting. It takes a lot of patients and a lot of strength and endurance, um, especially if you don't have the technique down, if you haven't built up calluses on your hands. It can also be painful. But it is certainly a possible thing to do.

I mean, people do it all the time. You've probably have seen television shows, whether they are fictional or documentaries, where people have done this kind of method, and YouTube is just full of instructional videos if you want to learn how to do this, and you may be saying to yourself that, hey, this isn't really a technology, um, but there are a few a few tricks or or hacks or whatever you want to call it that you can use that will move it a little bit closer

into the realm of technology, like adding a little bit of grit to the surface of the sticks to increase the action between them, or creating a simple pulley system using a sturdy strap to help you to to help make the movement easier. So I mean, like like the bow method where you have the the bow where the string is wrapped around one of the sticks, and you use that to make the spin it, Yeah, to spin it really really fast. So yeah, this is these are

basic tools, but basic tools are the foundation of technology. Yes, and we're not sure, I mean not just us, but humanity in general is not sure how long we have been using this particular form of fire starting. I've been doing it longer than we've been writing. Yes, and you know, at a certain point, sticks really don't hold up that

well to the tests of time. Yeah. So yeah, it's one of those things where you can't really necessarily go back and uh find find lots of evidence for exactly how you might be able to find evidence of a fire, but not necessarily know how they got it started right, you know, was this something that they used, the whole rubbing sticks together thing, or was this they found fire and brought it back? I think I think the oldest stick that I've seen mentioned in a museum website where

some four thousand years old. But that seems awfully young for this kind of thing, considering that, you know, we've been using fire in some form or another for more than a million years. Uh, so then moving on to flint and steel or other metals or technically other minerals as well. Uh, you've probably have heard of flint and steel, particularly if you play mind graft, because it's one of the things you can make. So flint is a hard sedimentary rock and it has a type of micro crystalline

quartz structure to it. Uh. Geologists call it shirt, which is just a great word. I call it. I call it bob. Uh. No. It's been used in toolmaking for a while, some some two million years. So it can break into very sharp pieces that structure, that crystalline structure, so it makes really good knives or spear or arrow heads. Um. So it's been used in lots of different types of tools. And when you strike it against steel, you end up

getting the spark that's really good for a fire. And actually my notes, I wrote flint gives off a spark suitable for starting a fire, but that's not really true. It's actually the steel that's giving off the spark. So here's the interesting thing. Now, this is going to be different when we talk about modern day lighters that use a very similar approach. But the idea is that you are creating the friction generated by this strike. You're trying

to strike it from an angle. You know, it's not like direct on, like slam iron against a piece of flint. You're you're you're doing this kind of angular motion. And the point is that you're trying to create friction generated by the strike to knockoff little pieces of steel or iron. I mean, steel really is is refined iron um and and that works because the flint is harder than the steel. Yes, so you you will actually have the flint knock little

pieces of steel off. Now, those pieces are heated above the ignission temperature for iron based on those tiny, tiny um particles, they're gett knocked off again, we're talking about that surface area to volume. The ignition temperature of iron is actually very low. Yeah, well comparatively when you get it into the tiny little pieces. Certainly if you're looking at it in bulk, very high. But but but you

might be asking, well, what else is going on here? Well, the presence of oxygen is what's allowing those pieces to heat up even more. Because iron has something called pyrophoricity, and you might say it was pyrophoricity. It means that it will ignite in the presence of oxygen. Yeah, and you might say, wait a minute, I have a wrought iron fence and I can't even remember a single day when it was on fire. Super not on fire. Yeah, it's probably the least on fire thing that's in my

house or around my house. It's because that has a coat of iron oxide on it. So iron oxide also we call that rust. But iron goes through this oxidation process when you have it in bulk. The heat generated from that oxidation process means that the it can be conducted through the rest of the material, and that's why it doesn't heat up to a point where it gets burns, burst into flames. But if it's a really really small piece that is suddenly exposed to oxygen, then there's nowhere

for that heat to go. It just ends up becoming this oxidized super hot mass, super hot for its size anyway, uh and can be very Uh can since become molten, which then you can use to set fire something yet tender tender usually usually UM. Humans have been using this method for some four to ten thousand years, which means, of course that that the earliest flint based fire starters.

We're not using steel at all, which was invented in the bronze and or iron age some uh, you know, less than four thousand years ago, right, so earlier stuff was using something else, right, iron pyrate, a fool's gold. Instruments of those types have been found dating back way farther,

and I didn't want to say that. Part of this technology is really also a tender materials technology issue, because as we have improved ways of creating tinder and carrying it and keeping it dry, we have been able to more effectively use flint and steel to create fire. Around the world, tinder has been made from everything from like simple bits of dried grass or bark to decaying tree fungus, which is apparently really effective at starting fires. I'm not sure.

I've never tried it. Um, and it's been carried in everything from really ornate brass or enameled boxes to go testicle leather. Okay, I I have no response to that. We're learning things. I do remember watching I think it was UM Survivor where the guy would end up getting a spark from flint and steel essentially and then lighting some tinder and then carrying a handful of smoking tinder to where he was going to light his fire, and the whole time I was thinking, please don't, please, don't

burn yourself, Mr nice Canadian man. And then of course he would make a fire um like a fire bundle, which would have a tin smoking ember inside of it, and that would allow him to carry his fire with him to his next site, where he would then use that ember to help light the fire, unless he wouldn't have to create a new spark. Uh. Not all tinder is carried already on fire. Some of it is just carried, so that's pretty frequently, just just kept very dry and safe.

Right at any rate, speaking of tinder, though, Hey, there was a thing called the tinder pistol, so it was softer than regular pistols. It's a tinder pistol. No, No, this was in It was sort of a step between the flint and steel kits and lighters that we have today, okay, And they were converted flintlock pistols. They consist of the handle and trigger of a pistol with a small tinder box where the barrel of the pistol would be pulling.

The trigger would pull back the lid on the tinder box and simultaneously engage the flintlock mechanism which would send sparks into the tinder. And now we we've talked a little bit on the show before about flintlock guns. It was in our three D Printed Guns episode. Yep. We also have an episode from way way back about the technology of fifteen ten where Chris, Chris Pallette and I

talked a lot about flintlock pistols and that one. So if you really want a full run down on the flintlock, you can listen to that old episode of tech stuff,

but a quick refresher just because there's such elegant machines. Um. So, the flintlock pistols hammer is actually a lever that holds a bit of flint at one end and is attached to a spring at the other end, and that spring connects to the guns trigger, all right, So when you pull the trigger, it springs that the flint edge of the hammer into contact with a bit of steel called a frizzen, which creates sparks which light the material at hand. In a pistol it would be gunpowder and in ours

it is tinder. So you you reload the spring by simply pulling back the hammer. Again interesting, not not difficult, um, but these these tinder pistols, though were household items. They really weren't meant to be portable, and all the models that I've seen included these really heavy legs so that

they could sit kind of elegantly on a table. Uh. Flintlock pistols were really new and expensive in the early to mid six hundreds, so it was definitely a measure of wealth to own such a contraption just for lighting candles and your tobacco products and etcetera. You know, one thing that I wanted to talk about because I thought, you know, it's again a very simple technology that a lot of us take for granted, especially since it's not that frequent that most of us come into contact with

us anymore. But just I want to talk about matches, and the reason is because it's a cool use of our knowledge of friction and chemistry to be able to create fire in a manageable way, and it really made

it much much easier to produce fire. Now. They're relatively recent inventions, although the earliest UH research dates all the way back to the late seventeenth century sight, and that's when a philosopher, physicist, chemist, professional smart person named Robert Boyle began to experiment with phosphorus, which is a pretty volatile material, and he coded a coarse piece of paper with phosphorus and then found that by moving a piece of wood coated and sulfur against that phosphorus coated paper,

he could produce fire. You just had to move fast enough for the friction to generate the heat necessary to get above that ignition temperature. But his ingredients were also kind of toxic, so it wasn't really practical to make that. As like, this is the new fire starting technology of the seventeenth century, So you get to a century later,

seventeen eighty French physicists invent the phosphoric candle. Now this is super interesting to me because I can't imagine what it must have looked like to light something using this thing. It sounds very traumatic. Yeah, So imagine that you've got a piece of paper or some strings coated in wax and it's been tipped with phosphorus and sealed in a

glass container. So you've got this glass container inside of which is this string or glass or a paper, And then if you wanted to light the match, you would have to break the glass because upon being exposed to air the phosphorus would ignite and set fire to the paper and or strange. Yeah, so in case of a need for fire, break glass. It's kind of the opposite of what we usually see. Yeah. Yeah, not obviously not practical,

very interesting, but not practical. Then let's see if I can say this word that that, as far as I know, didn't exist until this thing was invented in eight oh five. You have the oxy muriated match. It's it's also known as the instantaneous lightbox, which I think is a much nicer name. Uh Now, this was also kind of a

scary way to start a fire. So you would use little pieces of wood that had been treated chemically, uh so that when exposed to sulfuric acid, which serious stuff there, but when exposed to sulfuric acid, the wood would burst into flame. So you dip these bits of wood into sulfuric acid and you create fire. This Why don't Why don't Why doesn't every child? I think the sulfuric acid

alone answers that question. But yeah, it was interesting. And again this was all leading up to seven when a man named John Walker, an Englishman, invented the friction match, which were three inch long pieces of wood that were tipped with potassium chlorate and to many sulfide gum and starch.

So drawing this match against any rough surface like sand paper would cause these chemicals to mix, and because you had added heat from friction and oxygen from the air, they would end up bursting into flame they hit that ignition temperature and the boom, and you also kind of get a lot of sputtering, like this was a you know, it was just a little bit like a sparkler almost. Yeah.

One one description I saw said it was kind of like a listening to a bunch of firecrackers go off, not as loud, but she get those little bit and then uh, later on you would see very similar matches coated with sulfur and white phosphorus, which could be struck

pretty much anywhere, including like on clothing. So if you've ever watched movies or television shows where you have that person who just you know, uses the match and rubs it really quickly against pretty much anything beard or whatever that's a table top, essentially, that's these sorts of matches, but also has some drawbacks. So remember that way back when Boyle was practicing with his he had those toxic fumes given off, same sort of thing. The gas given

off in this ignition process was pretty toxic. So in fact, there were people who would market these um these matches, and I think they were called lucifers originally, and they said don't breathe in the few Yeah, O, white white phosphorus is bad times kind of not good. So there's the question. We have those matches you can lie against practically any service. Why can't we do that with a match that you buy today? Like you get a matchbook,

you take a match out of the matchbook. Why is it that if I, even if I try really hard to light it against coarse sand paper, nothing happens because all of the chemicals needed to create the ignition are not on the head of the match. Some of them are in the strip of paper that you rub the match against. Matchbook clever. So by limiting where I can

strike the match, I make it safer to use. Obviously, if you were to introduce enough heat to any match, then it was going to ignite, but on its own, it's not likely to do so unless you were again like exposing it to flame or something like that. So, like you say, the match divides up those those chemicals onto the striking surface and the match itself. So modern matches have chemicals that allow it to ignite evenly so

you don't get like that that crazy sputtering. And typically your match head has some quick burning chemicals like potassium chlorine on them. The box or matchbook has a strip containing some other chemical, usually something like red phosphorus, which does not those toxic fumes. Phosphorus does, yeah, which very important obviously. So yeah, when you strike those matches, the match to that that surface together, you get that chemical mix, you get the heat, you get the oxygen, you get fire.

So super interesting to me that that's how those those um developed. Then you have electric matches, which are not at matches there. They're essentially coils of wire and you run electricity through that coil of wire, and the resistance of that wire means that you lose some with the electricity into the form of heat, which often with electronics is something that's really irritating. Right Oh yeah, yeah, you

want to avoid that, and for example your laptop. Yeah, you want to make sure that all of those pathways are as efficient as possible. That are it's generating as little heat as possible, So that way you're getting the most out of your your energy pouring into it. Right. But if you're looking to create heat, you can very easily create a situation where you're going to make all of that resistance happen and build up as much heat as possible exactly, and then the wire will start to glow.

It's giving off photons and it's really really hot and you can ignite stuff with it. If you have ever used a car cigarette lighter, that's essentially how these work, which don't I don't think exists anymore in cars, Yeah, if you have an older car maybe. I remember I burned myself quite badly on a car cigarette lighter because I remember my my distinctly remember this. My father was telling me, like, this is hot. It's really really hot.

You don't want to touch this because it's hot, and as a kid, I thought that's not hot, and I touched it. Not my dad's fault, Yeah, I learned my lesson. But dad wasn't trying to like, you know, let him learn the hard way. He was actually trying to be very responsible. I was the irresponsible jerk in that case. So I want to I want to make that clear that my dad was not abusing me. I think I think most humans have a have a hot things are hot.

Story very much like that somewhere. But this is the same principle that electric heating surfaces use, right, Like, if you have an electric stove that kind of thing, it's essentially using resistance so that the flow of electricity generates heat until you're able to do something with that, whether that's light a fire or cook your meal. So that's what electric matches are. And they come in lots of different forms, not so much these days, I mean a

few of them do. Like in our camping episode. I didn't mention it because I wanted to talk more about fire making and in this episode, but I've seen a portable electric match. Essentially it's really meant to start fires, even in a camping situation. But it's it's not really that different from a cigarette lighter that in the old cars. Pretty much the same sort of thing, alright. So now we get up to uh, magnesium magnesium fire starters, right,

sometimes also called fire steel. This is basically a really efficient form of a flint and steel mechanism. Um you would draw a steel blade against a bit of magnesium or a magnesium alloy which would create these super hot sparks. Magnesium flames up around a three thousand degrees celsius that's about five thousand five degrees fahrenheit, which which makes it really useful for emergency situations because first of all, that's a that's a very bright spark that it's producing, and

second of all, it's it's really combustible. It's gonna combust what you need combusted. Yeah, no, no joke. All right. So now we're getting down to lighters like the butuane lighters that uh, you know, most of us are familiar with in some form or another. So they have a few important parts. One is the spark wheel, which is made up of hardened steel wire. It's a little bit that east spin with your thumb. Yeah, failed to spend with your thumb. In my case, I'm still really incapable

of using lighters. Yeah, I have very few occasions to use lighters, so it's not really something I do. But that's the case. I am too, I am too. I just happen to have one of the long braun style lighters shut. So the wheel grinds against the material that's like flint. Some of them even call it flint, but most of these lighters have a man made metallic material called ferro cirium in place of flint. Now, the flint being used in these lighters is different from flint and steel.

That that kind of method is the flint that you would actually find out in rocks, you know, as actual rocks in our own Yeah, you would, you would find it in the earth. Um. Now, in that case, the flint is the thing, like we said earlier, that breaks off a little pieces of steel and those heat up and that's what you used to light your fire with a lighter. It's the other way around. The steel is actually harder than this farro cirium material, and as the

pharaoh cirium that is oxidizing, that's sparking. So the steel remains pretty much the way it is. This this so called flint gets worn down over time because that's the stuff that's actually sparking. Yeah, that's that's similar to that process in that magnesium but that I was just talking about. Well right, yeah, it's interesting because it's the same basic principle. It's just it depends on which material it is it's

actually sparking. Uh. In this case, we also have a compressed spring that provides the pressure needed to hold that pharow cirium up against that wheel. You would imagine if you're using a lighter, then eventually you're starting to wear down that material because you're you're knocking off little pieces of it that are that's what's sparking. Ah, So you need the spring in order to keep the flint flush against the exactly. Yeah, So this this spring very gradually

extends as the flank gets worn down. Now, granted, it's not something that you would notice over you know, unless over a long, long, long period of time. In fact, you're more likely to run out of fuel with your life exactly, and that fuel tends to be buttane. You usually have a little canister that's in the base of the lighter that contains the fuel. It is controlled by valves, and when you press down on that little usually red button when you flick the wheel, that's what opens up

the valve to allow butane to fly through. Now, because you have valves, because you have this controlled release of butane, and because we learned a fire will sustain itself as long as it has fuel, because the flame is hot enough to keep it at that ignition temperature once you turn that wheel. Once you're good, you just have to hold down that little button button and as long as you have fuel that that fire should stay lit, assuming you don't run into something like really high winds that

interrupts that flow a fuel to the flame. So obviously it was really important to design this in such a way where you weren't going to get any blowback with the fire backdraft. Yeah, you don't want anything like that. So as the film, no, no, I have a soft spot in my heart, flat movie. But anyway, yeah, it's it's an interesting technology. So we thought, where can we go from here? And we thought about talking about blow torches, but there's a lot to talk about with blow torches.

And there was a choice between blow torches or are incredibly scary fire producing technology, and we decided to go as scary. We decided that flamethrowers are really the way to go. Yeah, so, uh, strap yourselves in, guys. We we couldn't resist. First of all, weaponizing fire not a new idea. I mean, you know, anyone who seen the documentary Robin Hood knows Prince of Thieves, you know that

one with Kevin Costner Um that one. Obviously they would use flaming arrows, but we've been using actual kind of early flamethrower ideas for very long time, like way back in fifth century b C. These were essentially tubes like brass tubes filled with a burning stuff, and a warrior would blow on one end of the tube, which would launch the burning stuff out of the other end of the tube, presumably at an enemy, hopefully fingers crossed. Now, when you get up to the seventh century C, that's

when the Byzantine Empire began to use Greek fire. This is terrifying stuff to read about. And we don't actually know what it was made of. No, we have some suspicions that was probably some sort of petroleum mix that had some other chemicals in it, but we don't know specifically the people who made this stuff. We're very very secretive in it because obviously it was a it was a trade secret. It was an advantage over all their enemies, right.

It is terrifying think of it. Think of being on a ship in the seventh century and seeing streams of flame going into the sky from the walls of city that you're trying to to lay siege to. You might have some second thoughts, especially if you're in a wooden chip, which you were at the time, that would definitely get like, guys, I foresee a problem. I am perhaps rethinking this idea. Yeah, so the way this would work again is they would have these brass tubes that would be connected to some

sort of reservoir. Usually you would also have a pump that would pump the liquid through the tube. It was a single action pump, meaning it was only working on the downstroke, and then you would have some lucky person whose job it was to ignite the fuel when it came out of the tube. There are some people who actually suggested that it's possible the Greek fire would even ignite upon connecting with water, which is interesting. It's not

impossible that that is the case. But there's the problem is there's no definitive account that tells us exactly how this worked. But it seems that there were more likely these warriors who would essentially hold a torch light the

end of this thing. Bad job. Yeah, not necessarily. You probably drew the short straw that day and it would pump out this these flames and once the pump had finished on its downstroke and goes back up again, the flames would stop because your fuel was cut off, and so the warrior would have to stay there in order

to ignite the next stream. Chinese warriors copied this approach and improved upon it by using double bellows, which could pump out flammable liquid both on the upstroke and the downstroke of the bellows itself, because it had this this double action going on, so you had a continuous stream of flames coming at you. Definitely gonna make you think twice before you try and storm their their ranks. Now,

these items, these weapons, we're really scary. They're absolutely devastating, but they were not portable because they were usually connected to some sort of reservoir. So's we're not talking about like a personal weapon. This is something that's attached to a larger structure of some sort. And eventually some thing else came along that was way more effective as a as a tool of war that essentially replaced flames for a good long time, and that would be gunpowder. Yeah,

gunpowder certainly changed warfare dramatically. Everything from the era of the knights and armor two castles to this kind of flame technology, all of that was sort of rendered moot once gunpowder came along. Although flame throwers did in fact come back into warfare, it would take it until about World War One the German Army began to introduce uh flamethrowers into warfare. It wouldn't be till World World War two that you'd see both access and Allied powers using

this technology. And it was pretty terrifying stuff because we we had the technology to make them portable. Yeah, because now it became a personal weapon, not just something that was connecting. Yeah. Absolutely. So not all developed developments and technology are things that we are necessarily like, hooray, yes, awesome. Some of them are like, wow, that is scary stuff. It's terrifying. It also looks really cool in video games.

I guess at a certain point I can't really argue movies like The Running Man, you know, Fireball, fictional flamethrowers are terrible. John always a little bit upset you guys doing this research. Well, no, because I was reading about what would happen. I mean, you're you're talking about burning fuel flying at people. So but to just focus on the technology and not the application of it, let's let's talk about that. So these flamethrowers were different. They were portable.

A single soldier could carry and operate one. And what it would consist of is a backpack that would essentially have three tanks on it. You have to fuel canisters and in between them you would have a pressurized air canister. So the fuel canisters, that's what has whatever the flammable liquid happens to be for your flamethrower. The pressurized air is what forces that fuel to go through the fuel

lines and through the gun that you're holding. Now, that fuel flows through to the gun, and that's where you've got to triggers. Essentially, one trigger is what allows the fuel to flow through and the other one is the igniter uh. And they had different ignititers depending upon the era of flamethrower. Like the early ones used resistance coil, very similar to the electric matches we were talking about. So you just have this really hot coil of wire.

The fuel would pass through it essentially or or against it, and that would hit its ignition temperature. The flame would start and of course once the flame started it was enough to keep that flame going, you could let go of the ignitior at that point, just hold onto the fuel. Same sort of thing with the more modern ones, except they use spark plugs. So you've got a battery and the battery provides electricity to the spark plug, which generates a spark. That's what allows the fuel to catch fire.

And again, as long as you've got fuel going through the flamethrower, you're going to be shooting flames out. So interesting stuff. But you know, let's not stop there. You know that that's terrifying all its on its own. You see a soldier shooting flame out, that's very intimidating. But you can also make very large mobile flamethrowers. Yeah, you can attach it to something like, I don't know, a tank. Now.

The reason why it gets even more terrifying with the tank is that not only do you have this enormous armored vehicle bearing down at you, the pump in this vehicle is attached directly to its motor, so it's so so the tank's engine, oh my goodness, is powering the flow of the fluid. Yes, so you can shoot it way further than you could with a handheld flamethrower, so you get the propulsion of fuel would go much further. And obviously, again a very effective intimidation tool, not to

mention just an outright devastating weapon. So yeah, those are those are the methods that we wanted to cover about technology that makes flames. Obviously we didn't cover other things like you can use light to make you can use lasers, you could use uh you can use lenses that focus light to a point. So there are other uh option is that we didn't cover. Maybe one day we'll do

a second episode. If if any of you guys out there are kind of pyros and you would like to hear more than definitely let us know, particularly if there is some method that you thought, you know, I was hoping you were going to cover it and we didn't. Let us know, tell us what we missed, and we will. We will consider doing a second episode. And uh, I feel that we are justified in doing this episode only because we have done episodes about how fire engines work.

We've done episodes on how the Boston fired alarm system worked. You know, we have all of that kind of stuff. So this is responsible We're getting response responsible journalists. We have to tell both sides of the story. Clearly, if I learned nothing from browsing through a journalism schools brochure I learned that. So, guys, if you have any suggestions

for future episodes of tech stuff right into us. Let us know our email addresses tech stuff at how stuff works dot com, or drop us a line on Facebook, Twitter or Tumbler or handle at all three is tech stuff H s W and we'll talk to you again really soon for more on this and thousands of other topics, because it how stuff works dot com