Deep in the library, two men sat by the hearth, smoking their pipes and gazing into the fire.
"The trickiest thing with machines running on the phlogistonic principle", intoned Quartermain, his white fur scarf muffling his already husky voice, "is that there's just no way to allow for fine control."
A mischievous gleam darted in his eye.
"Quite, quite." nodded Dr. Moreaux, missing Quartermain's repressed mania, distracted as he was by last night's memory of Maria's breathless confession in the pantry.
Quartermain continued, "You see the phlogiston exits the burning wood and is transferred into the water suspended above. Since water is what we call phlogotransmic, it holds the phlogiston, but will release it at the first opportunity.
By encasing the water, the phlogiston is trapped and can be used to drive pistons, which in turn drive wheels and so on, providing huge amounts of power. Say are you listening Moreaux?"
"Huh? Wha, erm yes of course." Moreaux, flustered, puffed on his pipe, smoke disguising his blushing cheeks. "Sorry old chap, yes, you were saying."
"So yes, power, and lot's of it. But we're only able to control it in the crudest of ways. A brass lever here, a steel piston there - it's all so manual and pedestrian. What we need is some way to let the phlogiston regulate itself, to somehow use very small changes in an initial condition to finely control the vast power inherent in phlogistonic mechanisms."
"But Quartermain, what on earth would that achieve?" frowned Dr. Moreaux, annoyed that his daydreaming was being interrupted once again by the ramblings of his old, and slightly batty friend.
"Why, the power to amplify! Allow me to show you my latest invention."
Moreaux's heart sank, the last time he'd seen one of Quartermain's half-baked inventions, it had cost him both his pudding, and his favorite pair of breeches. Not to mention Aunt Bessy's umbrage at the blatant and vociferous misuse of one of her hand-made custard tarts in the demonstration of a speed impeding device for over-enthusiastic omnibuses.
Quartermain stood and produced from behind his sitting-chair what looked like a long necked, stringed instrument. What appeared most bizarre was the lack of a chamber in which the sound would normally reverberate. In addition, a long, rubber tube snaked off into the darkness.
"Let me point out these devices here", Quartermain lifted the bulky instrument and leaned it towards Moreaux.
Beneath the six strings, where the sound hole would be on a normal instrument, there were six tiny diaphragms, linked to the string above them by small rods.
"As the string vibrates", Quartermain plucked one of the strings, "It causes the appropriate 'pushdown' to oscillate in step. Inside, a tiny pipe allows the passage of phlogistonated water to pass perpendicular to the pushdown. As the pushdown vibrates it alternately allows or impedes the flow of steam along its circuit. Each of the pushdowns has such an arrangement."
"But I don't see the point of this Quartermain."
"Ah yes, but I've missed out the really exciting part of the invention! The Phlogistonic Vehemence Attenuator!" Quartermain grinned manically.
"Try to imagine a busy town crossroads, when traffic flows across one direction, it impedes flow in the direction perpendicular. Even if the traffic being blocked is of a greater volume than the blocking flow."
Moreaux looked confused "I witnessed just that this morning at Charing Cross. A line of nuns strolled across the road, holding up a quantity of omnibuses, hansoms and barrows, but I dont quite see what that has to do with this."
"Precisely. Now, what if we could reverse the effect, so that flow was normally impeded, except when a minor cross-flow was in effect?"
"I'm still not sure I understand."
"Imagine a pipe containing a large quantity of fast-flowing, high pressure phlogistised liquid. Now place a valve in the middle. Opening and closing this valve will allow the travel and impedance of the fluid. The opening and closing is performed by a secondary, but much lighter flow that goes through a secondary arrangement perpendicular to the main flow."
"But if the main flow is under a higher pressure, wont it over-ride the working of the valve? If a nun crosses a road while there is no traffic, it will stop to let her by, but if she steps out under a speeding omnibus..."
"Very good point, yes, the lighter flow needs to control the heavier one without being over-ridden. In order to do this, we use a highly geared Archimedes screw driven by the control flow. Whilst it is turning, the main flow is allowed to progress, but should the control flow be stopped, so will the screw, and so will the main flow.
We can step up a number of these devices in order to amplify a tiny input signal into a much more massive one. Observe."
Quartermain reached over the hearth and pulled a drawstring, behind a tapestry, a large boiler was revealed, suspended above the fire. Quartermain tapped at a gauge, looked at his pocket watch and nodded to himself before reaching once again behind his chair and rolling a heavy box out into the middle of the room. Several rubber hoses trailed from the box to the instrument in his hands, and up to the boiler above the fire.
He pulled a well-oiled lever on the box and looped the strap of the instrument over his head. The box seemed to throb and strain with a vast, unbidden and as yet unleashed power.
With an arcing motion of his arm, Quartermain strummed the instrument and an almighty clang bellowed from the resonation of a vellum diaphragm set into the front of the box, causing the whole thing to skip, despite it's considerable weight, across the floor.
With some not inconsiderable dexterity, Quartermain began plucking individual notes with one hand, whilst holding down the strings against the neck of the instrument. The all-encompassing noise from the box mirrored his movements with only the slightest of delays. Small objects on the mantelpiece shifted uncomfortably and specks of disturbed ceiling plaster drifted down, settling on Dr. Moreaux's shoulders.
"Gads! Incredible!" Uttered Moreaux once Quartermain had completed his animated performance.
"Yes, I am planning on building a device that will allow the amplification of reverberations in the air - I call it a phlogistaphone. Imagine King's Cross where an operator will be able to address the entire station, rather than having to employ all those guards to announce the arrival or departing of each and every train! This could be the dawning of a new age Moreaux!"