He varies his magic tricks so as to minimize the possibility that any given audience member will see the same trick twice.

For that, being the number of the Elements, Principles, or Materiall Ingredients of Bodies, is an enquiry whole truth is of that Importance, and of that Difficulty, that it may as well deserve as require to be searched into by such skilfull Indagators of Nature as your selves.

to represent the imagination under the figure of a wing

the child is musical; having a musical ear