[432-10] Muse here means wonder at.
[432-11] Probably Prospero alludes to an old saying which meant, “Do not praise your banquet too soon; wait till it is over.”
[432-12] Among the strange shapes that danced about the banquet were deformed men from whose throats the flesh hung down in huge pockets, like goitres, and others whose heads grew from their breasts without neck and shoulders.
[432-13] Sometimes in Shakespeare’s days they practiced a curious kind of insurance. If a man were going on a long journey, he put out in the hands of agents a sum of money, under the agreement that if he returned he was to have a certain number of times the money he put out. If the journey was perilous, the agreement might call for five times the sum; if a safer journey, perhaps twice the amount. If the traveler did not return, the agents kept the sum put out. Gonzalo uses the phrase “Each putter-out of one for five,” to mean each man who goes on a perilous journey. He means that every traveler returning vouches for, or gives good warrant for, the wonders he has seen.
[433-14] Instead of That hath to instrument, we might read That has control of. The whole sentence means: “You are three sinful men whom Destiny, that rules this lower world and what is in it, has caused the never-surfeited sea to throw on shore; yes, and on this island which man does not inhabit; you who are among men the most unfit to live.”
[433-15] Water closes immediately over any cut made in it.
[434-16] Dowle means down, and the comparison means, as cut off a single thread of down from my plumes.
[434-17] Requit means here revenged.
[434-18] Whose refers to the word powers six lines before. The meaning of the remainder of Ariel’s speech is as follows: “Nothing but repentance and a clear life hereafter can guard you from the wrath that otherwise will fall upon your heads in this desolate isle.”
[435-19] The meaning of the preceding clause is: “Thus with the skill of life and keen observance of the ways of men, my humbler servants have done their work, each according to his nature or kind.”