Prokui can cast it on his own at level 25 with penetration of 25, wo he's been doing that.
I wasn't wanting the Summon Scorpio spell to fire on its own. As for requisite, they don't/can't make the cord out of plant fibers?
I think it's worth noting that, in Ars Magica canon, there's no proper inertia. Something propelled through magic stops moving as soon as the magic is cancelled, which is why Parma Magica resists a boulder thrown by magic.
Edited to add: As pointed out by Jonathan.Link below, the statement above is not correct.
That's not correct. The Vilano school of House Flambeau and the spell Invisible Sling of Vilano (Houses of Hermes: Societates) are examples that directly contradict this statement. Attacks that require finesse do not need to penetrate and require that the missile be mundane. If you conjure a crossbow and put a mundane missile in it, and aim to hit, it's largely the same thing as a Vilano based attack.
Yet the core rulebook states in page 85:
And in the examples provided:
And still you are absolutely correct. Regarding the "Invisible Sling of Milano", HoH:S page 38 clearly states:
I can't really see how this is not a contradiction, and would love any help in working out the logic behind those two statements being both correct. 
This is a restatement, extension if you will, of the second bullet point on page 86 of the Magic Resistance section.
This describes ballistic weapons of all sorts, including the Vilano school.
Makes sense, though the wording in the "Invisible Sling of Milano" made me think it would be a case like the water example.
Thanks for clearing that up, I gladly stand corrected. 
I've added a note to my first post noting it's not actually correct, to make sure nobody mistakenly takes it as good information.
Honestly, in-world, I still see this as a contradiction - the "jet of normal water propelled by magic" is also a ballistic weapon, is it not? So should its motion not be just as immune to MR as a Vilano projectile?
From a game perspective, however, it's perfectly clear and consistent: Any offensive spell must either penetrate MR or roll to hit, but not both. The rules for what MR does and doesn't affect are somewhat flexible as needed to accommodate that requirement.
If you can start the jet of water moving and then let it go to continue without aid it will penetrate the PM. If you made a spell that acts just like a water cannon ( i.e. pumps water at a high rate into a jet that must be aimed) then PM has no effect and you could knock someone down.
For something like the Ruins of Andresina (modern day Grand, France), what kind of financial/legal situation would this covenant likely be in? From historical records, this would be roughly on the borders of the Duchy of Lorraine, the Duchy of Bar, and the Diocese of Toul; about 12mi West of the wealthy market town of Neufchâteau (with the obvious castle implied in the name). Would they be independent, flying under the radar due to lack of noteworthy resources (some pigs and barley) and some taxes thrown at the Holy Roman Emperor? Would they be under the vassalage of one of the Duchies or the Diocese?
What would be the likely effects and who would be the main people to react if they notably increased revenue with installing windmills (a recent invention) and rebuilding the ruins to what it was in Roman times?
Sanagos has finished reading all of his books on Artes Liberales, now having reached 20 in the ability. Except for his correspondences, he has yet to actually write a single piece of work; but could produce a L10/Q12 summa in four seasons (or L6/Q24 in three). The next question is figuring out what he will do next.
Yes? These are all depend upon the saga. What are the covenant's hooks and boons? Sometimes framing the questions while understanding the hooks and boons makes it easier to work through the problem. Whenever I'm working an angle on a story, I'm going back to the hooks and boons to determine the direction, and then take advantage of characters' story flaws to get an idea of who to involve/not involve.
If nobles suddenly saw their lands being enriched, or unclaimed lands being enriched, well, they would be strongly interested in acquiring their (fair?) share, if not acquiring the land outright. There isn't a hard and fast, or correct answer here, it all depends upon the stories your troupe wants to tell. And as long as you can sell the motivation for the NPCs as being "authentic" then I think you're golden.
So, he has a score of 20 in Artes Liberales. I don't know who Sanagos is, or why I should care about him or what he does. This seems to be a cross-post from your actual play thread. He appears to be a magus, has he considered integrating Aristotle or Plato into Magic Theory so he can get that sweet +20 bonus to his lab total (although, I would limit it to his MT score).
He's in the first post of this thread.
That's so 4 months ago! I still can't figure out who this guy is, except he's obsessed with the Fibonacci sequence in particular and mathematics generally. Perhaps he discovers some link between the Golden spiral and where gifted children will be born... Or something. How do you need advice about him?
Advice includes ideas for what to do with him.
I gave you an idea. I mean, two, actually.
Yes, but you asked why/how I wanted advice; so I told you. I never said you hadn't given me advice I couldn't use.
I was going for an unspoken, I'm sure you had some idea when you created him, what did you have in mind...
He and Prokui were originally created as a snapshot, someone without any (current) proactive goals, yet have incentive to stick around. For the beginning of the campaign, they were to be the voice of exposition & experience, as well as a safety net for the players with their very first characters. As it stands, the party is turning out to be fairly competent; so the elder magi are narratively permitted to be more present in the plot.
It's important to remember that Jerbiton aren't ruled by a relentless pursuit of their Arts, the concept of sufficiency is probably the norm among the House, though not exclusive to Jerbitons, nor does every Jerbiton have to practice it.
It does make sense that a Jebiton has a mundane thing that Sanagos is totally geeking out about. Usually it's painting, sculpture, some culture of some sort, but mathematics is entirely appropriate. Such a character as Sanagos would be one who sees the mathematics in everything, it would not surprise me if his Intellego spells gave precise measurements of things, that he examines things that seem to stand at odds, such as things that appear beautiful or pleasing, but are in line with the Golden ratio...
grin If he doesn't have a familiar, the Bjornaer can discover that he has a chambered nautilus heartbeast....