The meter of Longfellow’s poem is built around a four-beat rhythm whose pattern changes from line to line. This type of meter is known as accentual verse, which means that the meter is determined by the number of stressed syllables rather than the total number of all stressed and unstressed syllables. To see how this variable rhythm plays out, consider the opening stanza (lines 1–5):

     The tide ri-ses, the tide falls
     The twi-light dark-ens, the cur-lew calls;
     A-long the sea-sands damp and brown
     The tra-vell-er has-tens to-ward the town,
           And the tide ri-ses, the tide falls.

The above breakdown makes it clear how, even though each line has a different number of syllables, they all consist of four stressed beats. Accentual verse like this has a long history in the English language, dating all the way back to poetry written in Old English (also known as Anglo-Saxon). Perhaps the most famous poem written in accentual verse is the Old English epic, Beowulf. Longfellow’s choice to use this metrical form therefore places his poem in a lineage with ancient roots, which helps evoke an overall sense of timelessness.

Because accentual verse is determined simply by the number of stressed beats, it isn’t typically helpful to analyze the meter with traditional scansion. However, in Longfellow’s case, scansion proves unusually illuminating. Let’s take another look at the opening stanza, this time breaking each line down into distinct metrical feet:

     The tide | ri-ses, the | tide falls                             [iamb, dactyl, spondee]
     The twi- | light dark-| ens, the cur- | lew calls   [iamb, iamb, anapest, iamb]
     A-long | the sea- | sands damp | and brown        [iamb, iamb, iamb, iamb]
     The tra- | vell-er has- | tens to-ward | the town,  [iamb, anapest, anapest, iamb]
           And the tide | ri-ses, the | tide falls.                [anapest, dactyl, spondee]

Breaking each line down in this way reveals that the poem has a dynamic meter that frequently switches between rising and falling meter. The term rising meter refers to any rhythmic scheme emphasizing metrical feet that start with an unstressed syllable and finish with a stressed syllable. Iambs (unstressed–stressed) and anapests (unstressed–unstressed–stressed) are both types of rising meter. By contrast, falling meter emphasizes metrical feet that start with a stressed syllable and finish with an unstressed syllable. Trochees (stressed–unstressed) and dactyls (stressed–unstressed–unstressed) are both types of falling meter. As its name indicates, rising meter creates a sensation of upward movement, almost as if the poetic line is building something up. Likewise, falling meter evokes a sensation of downward movement, as if the poetic line is collapsing. The ceaseless shifting between these two meters powerfully mimics the ceaseless oscillation between the rising and falling tides.