Which Professor created which obstacle in Harry Potter and the Sorcerer's Stone?

Question

I looked at the forums sffworld and coolscifi as well as this discussion area but could not find the answer...

It is clear that Dumbledore created the mirror at the end of the Sorcerer's Stone and obviously Fluffy was Hagrid’s addition to the obstacles Harry (Hermione and Ron) had to work through but what about the other obstacles?

Which Professor created which obstacle?

Answer 1

Hagrid tells us which teachers are contributing protections:

“Well, I don’ s’pose it could hurt ter tell yeh that… let’s see… he borrowed Fluffy from me… then some o’ the teachers did enchantments… Professor Sprout – Professor Flitwick – Professor McGonagall –” he ticked them off on his fingers, “Professor Quirrell – an’ Dumbledore himself did somethin’, o’ course. Hang on, I’ve forgotten someone. Oh yeah, Professor Snape.”

— Chapter 14, Norbert the Norwegian Ridgeback

This makes it a simple process of logical deduction and elimination.

Midway through the chambers, Hermione lists those which they’ve encountered so far (just after they’ve finished the chess game).

“What do you reckon’s next?”

“We’ve had Sprout’s, that was the Devil’s Snare – Flitwick must’ve put charms on the keys – McGonagall transfigured the chessmen to make them alive – that leaves Quirrell’s spell, and Snape’s…”

— Chapter 16, Through the Trapdoor

At the very next obstacle, they encounter the troll. The chamber after this has the logic puzzle involving the potions, so this is clearly Snape’s work.

By a process of elimination, we can deduce that the troll is Quirrell’s doing, or just wait for Quirrell to admit it in the final chamber:

Certainly. I have a special gift with trolls – you must have seen what I did to the one in the chamber back there?

— Chapter 17, The Man with Two Faces

Finally, as you said, Dumbledore provided the mirror of Erised.

So the protections were as follows:

1. Fluffy – borrowed from Hagrid
2. Devil’s Snare – planted by Sprout
3. Flying keys – charmed by Flitwick
4. Wizarding chess – transfigured by McGonagall
5. Mountain troll – set up by Quirrell
6. Logic and potions – cooked up by Snape
7. Mirror of Erised – designed by Dumbledore

Answer 2

Hagrid: Fluffy

Sprout: Devil's Snare

Flitwick: Keys

McGonagall: Chess

Quirrell: Troll

Snape: Potion Puzzle

Dumbledore: Mirror Erised

Answer 3

I believe that this was answered in the book as the three went through each obstacle, but I might be wrong. I don't have a copy of the book near me.

Here is what HP wiki says, which makes sense:

After that, the Stone was placed in a special chamber and guarded by seven enchantments and creatures, provided by the professors at Hogwarts: Professor Sprout's web of Devil's Snare; flying keys, charmed by Filius Flitwick; a life-size board of Wizard's Chess, transfigured by Professor McGonagall; Professor Quirrell's mountain troll; Professor Snape's potion riddle; and the Mirror of Erised, placed there by Albus Dumbledore. Hagrid's massive three-headed dog, Fluffy, guarded the trap door through which the chamber lay. In order to keep them safe from Fluffy, Dumbledore forbade the third-floor corridor to all students.

Answer 4

Actually, it is quite obvious to any person who has adequately read the book, that it was Professor Flitwick who made the Wizard's Chess game, and Professor McGonagall who created the obstacle of catching a flying key. These keys are not completely transfigurated, but there is no known charm that Professor Flitwick could have performed to attach wings to the keys. Another reason; the game of Wizard's Chess was not transfigurated, but rather enlarged using the charm Augeo. Not to be confused with the Engorgment charm, Engorgio.