We know from TSE 46-47 that alchemical reagents can be mass produced. In canon, that's limited to Greek Fire, but we also know that Roman alchemists made enough concrete to build impossible edifices, and during the lifetimes of our magi, it's likely that gunpowder will likewise be mastered.
So. Say my intrepid natural philosopher wants to develop a means of mass-producing purified, weapons-grade steel. By default, this is a level 5 reagent unless I want a material that gives a bonus, where one dose creates enough for a dagger (though Magnitude can up the size) - blast furnaces at the time are not capable of reliably controlling carburization, and actually crucible-firing the iron ore as the Muslims can do requires a Mythic Alchemy guideline.
Would a Lab Text allowing mass-production alchemists' workshops for controlling steel purity (likely similar, mechanically, to the TSE workshops for Greek Fire production, but without the risk of a horrible explosion) require a Minor Breakthrough or just an experimental side effect?
Experimental Philosophy (A&A p.67ff) is not Hermetic magic. The experimental philosopher can indeed Experiment (A&A p.71), but applying concepts of Hermetic magic like Original Research (HoH:TL p.26ff) is a mulligan.
If you look up TSE p.46f Greek Fire closely, you find that the author formulates historical facts in terms of A&A Experimental Philosophy. So, the question you need to get answered by your troupe first is, whether changing history and introducing reliably controlled carburization of steel is within the scope of your campaign.
If so, then your experimental philosopher - perhaps inspired by an experimental side effect (ArM5 p.109) - can over the years set up the supply chains and technical infrastructures for this, starting with C&G p.65ff The Workshop and its innovation with Labor Points, as did the Greek and Arabic alchemists from TSE Greek Fire.
I'm not as sure of that - Integration is indeed a general feature of most Hedge Magic (HMRE 16), so it does stand to reason that Original Research is applicable as well (and experimental philosophy is indeed a form of hedge magic). One could argue that experimental philosophy is inherently limited in its capabilities compared to preternatural magic, but experiments to push those limits are well within theme.
You're right, though, that TSE does say that it's more a matter of workshop innovations and superior raw materials (that is, mundane innovation rather than magical) that allows Greek Fire to work, so I agree that concrete, gunpowder and steel workshops would be better served through C&G's systems, if a player wanted to make a story about using such natural magic and technological advancement. Mundane inventions don't have a development system like magical breakthroughs, sadly, but they do have a system for being put into place once developed...
Yeah, except that the ones who'd use that most (magi) are able to Creo-copy it. (Which does kind of damage the existing fatigue economy...much more easily than going to the effort to befriend a sahir does.)
Not really. Either you're spending a ridiculous amount of apothecary resources on a Monte Carlo bet, or you have Finesse well beyond mortal norms - and that's to create one dose.
Creo, you'll get a lifetime's supply of your stuff for four vis, and it will be functional tonic.
on the other hand, ReHe uses no vis, and can be cast numerous times a day. The only real difference is the need to have some grog with an apothecary skill scour the countryside for ingredients.
Kinda depends on how rare Vis is in your saga, neh?
If it's common and plentiful, Creo is probably the best solution.
If it's rare and valuable, Rego is plausibly the better choice.
Quite. A failed Finesse roll has the same consequences for Creo and Rego replication of Reagents and Theriacs. Check A&A p.70 box Replicating Formulae with Hermetic Magic: "..., but is subject to the same design restrictions, including the Finesse roll."
If you fail the Finesse roll on Creo-craft, you get something that's ugly, not something that doesn't do its job as Tonic of Gold. The bottles containing the tonic are plain, unmarked clay mugs or something. Maybe the tonic tastes terrible.
Anyway, if you're making large quantities (as in large-magnitude groups), four vis is usually going to be a lot cheaper than a thousand bottles' worth of material.
Sounds like you're pretty far into the house-rules territory then. If you're ruling differently for Creo than for Rego here, then you're not using the same "restrictions, including the Finesse roll." You're giving different restrictions to one than the other. That's fine as a house rule. But we don't usually debate these things with house rules unless we're specifically stating that we're debating merits/implications/whatever of house rules.
If you look closely at Covenants p.49 box, you find "Creo Magic draws on the realm of Forms to produce things, which are always at least roughly right." And in HoH:S you find far more precisely
(bolding mine)
Putting all this together, a Tonic of Gold is an artificial object, the consequence of which is clearly restated on A&A p.70 box Replicating Formulae with Hermetic Magic.
EDIT: You should discuss with your troupe, whether a ritual spell creating - say - 100s of Tonics of Gold requires a higher Finesse+Int target than a spell creating a single one, because it creates far more than an experimental philosopher can create in a season. Check for this HoH:S p.60 and Covenants p.49 box again.
That's why in the past there has been discussion about the added magnitudes for complexity providing a bonus to the Finesse roll. I am aware of no reason that couldn't be done. And if it can be done there, it can be done elsewhere. I would expect you want some limits, though.
Also, a castle over a few hours is not as sped up as you might think. Compare it to doing a spell in 1 round for something that can be done more quickly than the castle, like making a suit of armor. That it's not reduced to a single round is helpful.
It also breaks Twinning the Tome - which expressly is complex as hell.
Furthermore, ArM5 77 says that you're always going to get a functional item if you use Creo to craft; the devil is if you want to create a high-quality item or an attractive one. A cloak created with no Finesse will keep you warm. You're going to get a tower if you Conjure the Mystic Tower, and it will be a tower suitable for living in, setting up a lab, and defending against attack.
We also have a spell for exactly copying something which requires an Intellego requisite and +5 magnitudes for intricacy. No word on whether that generalizes.
I thought magnitudes for complexity/intricacy reduced, if not removed, the need for a Finesse roll?
One magnitude reduced the Ease Factor by 3, or am I remembering someone's house rules?