or rhetorical stress,
14. Strong rhetorical stress will almost always lengthen if required.
or place in verse will quantify.
15. The place in verse, if cunningly managed by the poet, will lengthen or shorten.
Commonness of monosyllables.
16. All monosyllables are common, the articles being, however, least susceptible of lengthening, and the indefinite perhaps hardly at all.
§ C. Equivalence and Substitution
Substitution of equivalent feet.
17. The most important law of English prosody is that which permits and directs the interchange of certain of these feet with others, or, in technical language, the substitution of equivalent feet.
Its two laws.