But the time element of a poetic foot is important, as it explains the seeming irregularities often met with in verse. An additional syllable may be added to a foot or subtracted from it when the time of the foot or verse is not changed. By rapid utterance two syllables are often equal to one, and in this way an anapest is frequently used with the time value of an iambus. In like manner a pause may sometimes take the place of an unaccented syllable. Both cases are fully illustrated in Tennyson's well-known lyric,—
"Break, break, break,
On thy cold gray stones, O sea!"
In spite of the seeming irregularity of this poem, the presence of the proper time element, together with the regular accents, preserves its metrical harmony.
There are few poems without slight metrical irregularities. The meter is varied to prevent monotony, to give emphasis to a word, or to respond better to some turn of the thought or feeling. Take, for example, the following couplet from Wordsworth:
"To me the meanest flower that blows can give
Thoughts that do often lie too deep for tears."
The meter is iambic pentameter; but the first foot of the second line is a trochee, and emphasizes thoughts with fine effect. The time of the line remains unchanged.
In Milton we read,—
"Leviathan, which God of all his works
Created hugest that swim the ocean stream."
