Observe the motion of the surface of the water which resembles that
of hair, and has two motions, of which one goes on with the flow of
the surface, the other forms the lines of the eddies; thus the water
forms eddying whirlpools one part of which are due to the impetus of
the principal current and the other to the incidental motion and
return flow.

[Footnote: See Pl. XXV. Where also the text of this passage is given
in facsimile.]

On draperies (390--392).