Imagine the magi find that the door to a tower is enchanted, or a statue carved from a rock in the middle of a forest. Without removing the object and transporting it back to the lab, can they investigate it? Are there rules in any of the supplements for how they would investigate this? If not, how would you handle it (I'm pretty sure how I'm going to handle it already, but am interested in other views)?
And connected to this idea - could you investigate the item from your lab via an arcane connection, e.g., a splinter of wood from the door?
You can work out how much and what type of vis is in it using basic Intellego Vim spells, and if you can cast a spell to communicate with the enchanted object / read its memories you might be able to extract useful information that way (HoH:TL pg 74 has some spells the Quaesitors use, but they're high level).
For an actual proper Hermetic "Investigation", though, I think you're looking at trying to build a lab around the object. By covenants you can build a Basic (-3) Outdoors lab in a season, but it's not going to be very good.
RAW [core:158] is pretty clear: «Magic items cannot be investigated with simple magic spells. Investigation requires that you spend at least one season in the laboratory to discover what magic an enchanted item contains»
I am most inclined to say no. If you twist my arm, I would add 20 to the effective level for purposes of investigation. At least.
There are rules in Hermetic Projects on how to enchant items which do not fit in a normal lab. (The Shipyard IIRC.) They might be applicable to your case too. I don´t know.
I'd like to build a little on what salutor says here.
You definitely cannot investigate such items in the way that you would in your lab, to me that means that you do not get to generate a lab total that lets you figure out the items powers and how to activate them. However just because you cannot Investigate the item with a lab total doesn't mean that you cannot investigate the item in the ordinary sense of the word.
There are however a number of things you can do circumstantially. Most of these are mundane activities that anyone with the wits, time and inclination could do.
Think of the classic scene from lord of the rings where Gandalf is trying to open the door to Moria by drawing on his knowledge of how such door-opening magic works in general. He doesnt know the code word and he certainly doesnt have the time to build a hermetic laboratory around the door much less to drag the door back to his lab. Instead he just has a go at it by trying out the most common pass-phrases and later with the help of one of the hobbits (i forget who) by looking at the riddle. Magi in ars magica can do much of the same stuff.
these are things that allow you to guess at an items powers, like what shape and material the item is made out of. e.g. rubies give massive bonuses to investing fire magic into the item so an item that incorporates rubies in its design is all other things being equal more likely to have fire-based powers.
likewise things with expensive materials and gemstones require more vis to open for enchantment and so are more likely to have many powers and simply be more powerful because they are more expensive to make.
I would imagine that many magic items also give clues to their function by their appearance. say e.g. that a ruby-tipped wand that creates fire-blasts might be decorated with motif's of flames or fire or whatever.
Since magic items are easier to make when they are activated by actual physical actions many items are activated by interacting with them so if you are willing to risk it you can also try to set off the items powers by poking at it. Maybe the magical statue can "plays a recorded message" when you pull its finger. In that case you can activate it by pulling its finger regardless of whether you have investigated it in the lab or not. You just have to figure that out on your own and risk setting off a potentially dangerous power.
If you can get the item in question to set off one of its power you can likely also determine the casting sigil of the magus who made the item. If you happen to know who that sigil belongs to then you can likely also deduce a lot about what the item might be able to do. Say you find a magical door with a casting sigil that belongs to that one magus who was famous for crafting that one teleportation-door that is activated by making puns about ham over at the neighboring covenant you might want to try to make ham and other food related puns at the door in case said magus had habit of crafting similarly activated items. Or in a less extreme case perhaps you know that the magus who made the item specializes in a certain TeFo combination or has a magical focus or some quirk of personality even, that you can use to your benefit.
If you have a spell like sight of active magics or if you are generally good with InVi you can also determine the TeFo of any powers that are active when you encounter them and probably also a lot about the actual function of said powers.
Of course there is not guarantee that any of these will work since magi are under no obligation to design their items in ways that give off some the functionality of said item. Likely many magi will opt not to design their items to give away their function and if you have encountered such an item you are out of luck. But such items dont make for the most interesting stories because your only option to study it, is to wait for the story to end and then roll the dice on your InVi(investigate magic item) lab total.
Related to this - is there any more information regarding shape and material bonuses beyond page 110 of ArM5? Is there another table in any of the supplements? I feel these really help the mystical atmosphere and realism or "credibility" and would like more of them.
There is also a mystery virtue called "Vulgar alchemy" that allows people to "discover" their own new S&M bonuses. This virtue is introduced in The mysteries revised edition and provides a neat way to sneak in new S&M bonuses you feel like you need them as a storyguide.
I can't speak for Tellus specifically, but in the past when it's come up I think people have had two key problems with it:
It requires a virtue to do, whereas people had previously assumed that it was something that any magus could do automatically.
Developing a bonus to the point where it can be used by other magi is a long and involved process, arguably for relatively little gain. A lot of it can be done whilst you're doing other things, which softens the blow a bit, but it does tend to lead to the suspicion that the vast majority of Shape and Material bonuses in the Order have been created by White Swans in the Order of the Green Cockeral trying to progress to the next degree rather than people doing Vulgar Alchemy for its own sake.
I very much agree with @Salutor's two points, and get very curious about @Tellus's words «as written», which seems to imply that it could be mended.
I have always read the published bonuses as mere examples, and by the principles of magic, It seems to me that the shape and materials bonus applies whether or not the magus know about them,. He could discover a bonus, but he cannot invent it, because it was always there.
A Pralician's Comprehend Magic Ability can reveal some basic information about enchanted items and can multiply their Magic Theory for an actual in lab investigation.
the ruleset really is quite strange, but more relevant to the topic at hand it establishes the point that Shape & Material bonuses are not limited to the list of things in canon and that if you want more to exist you should feel free to make them up.
I assume that the primary reason for something not being covered in the canon material is that it has not been relevant to the authors of the various splatbooks and that the core book was limited to 1 page's worth of bonuses. In other words for purely out-of game reasons.
you want a statue to have a +4 bonus towards investing effects that animate said statue? Bam that's a totally fair bonus.
You want a bonus that improves an item but you want your players to not know about it with a Magic theory roll? Some magus came up with that bonus recently and the player characters have not heard about it yet.
That being said I do agree with previous posters that Vulgar alchemy is weird in the sense that the virtue kind of suggests that Vulgar alchemy is the way in which new S&M bonuses come about. In the past i chose to view it as an example of an in-game mechanic that was added to provide concrete guidelines for players to come up with new S&M bonuses rather than as attempt to exclude the process from hermetic magic. I have not analyzed its numbers sufficiently to comment upon how well it was designed.
You could choose to fully integrate Vulgar Alchemy into Hermetic Theory and then add a virtue that reduces the integration time to the list of alchemy mystery virtues, I suppose.
Adding S/M bonuses also messes with the Blending with Substance part of Inscription on the Soul, doesn't it, by changing the enchantment level required to blend a particular substance?
Another thing that occurred to me, which I may as well ask here as it's still related I guess, is that I was surprised not to see any mystical/legendary things in the shape and material bonuses - I mean like, dragon scale, phoenix feather, basilisk tooth, unicorn horn etc. Seems like the kind of thing wizards would traditionally seek out (yes they might do so for an arcane connection or vis, but still). Is there a reason for such things being omitted?