They had birthed this idea fuelled by alcohol hangovers and nicotine addiction; they refused to give up now.
Already covered in grease, heavy leather gloves on and the shirt rolled up past their elbows, Gale began fitting the parts of the motor they had created to the bicycle. Everything was delicately balanced, they started from the rear, attaching the drive crank and bearings, followed by the connecting rods. They were flipped out the way before the main body of the engine was lifted, a heavy piece of steel that was firstly strapped into place and then, once the position was confirmed, bolted in place. Out the top Gale pressed down the two-piston heads, her ears pricking to the sound of the crankshaft going around within its belly, turning a full circle and inevitably rising again. The pistons were different than before, Gale had replaced them with brass tubes six inches in length, lubricated it with grease and a rubber seal, before sliding a metal bore down it. Gale manually turned the engine again, faster this time as they listened for the muffled sound a dying hiss of a spark. Each time the engine clunked, the arm rising and falling, powering on the next rotation until it hissed and sparked again.
Rocking back onto their heels, the smith took up next lot of piping, fitted them, and moved up to the next stage; the fuel tank itself was nestled to the front of the bicycle and had been modified to feature its own slot for its own igniter of sorts. The butterfly valve was fitted between the engine and the fuel tank, the wires were clipped into the handlebar and the internal panel twisted when Gale rolled the handlebars forward. It was at this point Gale took a pause to gather their thoughts, their fingers followed the journey from the back to the front, the mouth moving as if to recite the physics each part would be placed under.
"Connectin' rods is connected to t' crankshaft. When under pressure from t' fumes it pushes t' pistons up, which allow t' fumes out t' exhaust."
The smith tapped the shaft of the pistons,
"Same time, t' intake comes in, 'nd when t' piston comes back down, makes a spark, 'nd then repeat."
Gale winced then, rubbed their brow - leaving a smear of grease across it - and erred.
"Nay, wait. It uh. Fuck." It was difficult to articulate, the finger tapped harder against the engine, before they withdrew it, "Vapour comes in, gets hot, expands, pushes t' piston up..."
It was more difficult to explain due to Gale's lack of formal education, let alone lack of exposure to the sciences that the Gollies so hungrily guarded. Puffing their cheeks, they focused on the journey up the rest of the bicycle. The valve was easy, it determined how much gas was released into the engine, which in turn determined how quickly it worked; more gas, more pressure, and therefore faster turning. The smith took the next part of the remaining tools and pieces available; it was much like one of the pistons from the engine, but this time smaller - another fire piston, this time fitted with a spring that compressed as it rose and snapped back when released. The top of this was attached to another wire that was fed down back to the engine pistons. The wire was hooked over the top of one of them, neatly tied off and rolled up tightly.
Lifting the tied piston manually, Gale followed the wire up to the upper piston and watched it extend out an inch and a half before easing back down into the fuel tank with the easing wire. Gale exhaled, leaned back one last time to inspect everything was in place and retreated back into the forge proper. After a few moments of clattering about, Gale returned with a cigarette between their lips and a flask of lamp oil in hand - the distinct scent of kerosene permeating the air as they returned to the bicycle. Straddling it, they unscrewed the cap in the fuel tank, poured the lamp oil into the belly and sealed it up. The smith straightened, leaned back on the saddle and pulled the fire piston in the top of the tank back.
Here goes nothing.
Gale released it.
The spring-loaded piston shot forward, hissed and grew silent.
Nothing.
Fuck.
Gale pulled it back again, released, heard the hiss and then nothing.
Work. Dammit. Work. I want to sleep.
There was a tut, this time sitting further forward on the seat, leaning right over to curl a hand around the handlebar - they twisted it forward and in turn, the butterfly valve opened a crack. Gale pulled the piston up again and released it.
The clunk was loud, followed by a wheeze of noise. Determined Gale pulled the fire piston back again, and again, and again, each time the wheeze grew louder. It turned into a splutter, belching and spitting. Gale heard the crankshaft move, a begrudged squeak of noise that seemed reluctant to start. Gale pulled the piston again, twisting open the butterfly valve; the engine released a rumble, coughing now as it vibrated into life. The rear pistons rose, loitered at the top, and then slammed down once more.
The motor released a bark, the crankshaft beginning to spin and take possession of its own momentum. With each rotation the machine grew louder, snorting as it grew hot, the tank piston now recoiling back and forth of its own accord. The sound passed through them, arms shaking as it continued to spit, cracking turning into booming that reverberated off the walls of the smithy.
Wide-eyed Gale felt their lips move, their form trembling as they grinned.
What a noisy monster they had created.
Beyond the courtyard pedestrians were stopping, the nervous voices of others as the alien sounds roared into life - explosive, much like the sound of the illegal flintlocks - picking up volume. Gale clambered off it, watching the rear wheel go around, their hands clamping around their ears as the beat grew consistent. Black smoke was belching from the back, the burning lamp oil passing through the system, but clearly working and pushing the wheel forward - even if the resulting sound was beginning to grow deafening and the stench was becoming increasingly awful.
"Fuckin' aye!"