The Principles of English Versification
Chapter 3
METRE
_Elements of verse rhythm._ The simplest metrical unit is the syllable; the next higher unit is the foot, a group of syllables; the next higher unit the line, a group of feet; then the stanza or strophe.
In some prosodies--as the French and Italian, for example--the standard unit of verse is the syllable. The first essential of a line is that it have a certain number of syllables; the accents or stresses may, theoretically at least, fall anywhere in the line. In English verse also the syllable has sometimes been regarded as the unit, but for the most part only by a few poets and prosodists of the late sixteenth, the seventeenth, and eighteenth centuries.
The foot corresponds in English verse to what has been described in