How do we divide syllables when scanning a poem?

Question

In this line from Donne's A Valediction: Forbidding Mourning,

It leans and hearkens after it

I would scan it this way:

It leans and hear-kens af-ter it

However, my dictionary says that hearken is divided into heark·en not hear·en, although I would pronounce it as hahr-kun. The case is similar with words containing suffixes such as stalking in the following line from Wyatt's They flee from me:

With na-ked foot stalk-ing with-in my cham-ber

I would pronounce stalking as stal·king not stalk·ing.

So, how do we break words in scansion? Do we rely on the way we pronounce them or on the way dictionaries break them?

Answer 1

The question is based on a misunderstanding about dictionary notation. The question says

my dictionary says that hearken is divided into heark·en not hear·en

(sic—I presume hear·en is a mistake for hear·ken). But these dots do not represent syllable divisions! The Merriam–Webster dictionary, which is typical of dictionaries using this notation, explains:

The centered dots in boldface entry words indicate potential end-of-line division points and not syllabication. These division points are determined by considerations of both morphology and pronunciation, among others. Further discussion of end-of-line division is contained in the section of that name within the Explanatory Notes. In this book a consistent approach has been pursued, both toward word division based on traditional formulas and toward syllabication based on phonetic principles. As a result, the hyphens indicating syllable breaks and the centered dots indicating end-of-line division often do not fall in the same places.

_{‘Guide to Pronunciation’. merriam-webster.com}

So the dots indicate where to put a hyphen when breaking the word at the end of a line in printed text, and do not indicate syllable boundaries.

But in any case, for English scansion it does not matter what you do with the consonants, because the stressed and unstressed syllables are identified by their vowel sound, not by the consonants on either side. A common way to write scansion is to mark the vowels only, for example with / or ´ for a stressed syllable and x or ˘ for an unstressed syllable:

 x    / x   /     /  x    x  /   x   /  x
With naked foot stalking within my chamber

This notation for scansion makes it clear that the vowels contribute to the rhythm and not the consonants.