In book the second, page the tenth:

The stress of all my proofs on him I lay;

And now proceed we to our simile.

Imprimis, pray observe his hat:

Wings upon either side—mark that.

Well! what is it from thence we gather?

Why, these denote a brain of feather.

A brain of feather? very right,

With wit that's flighty, learning light;

Such as to modern bard's decreed: