Poems Of Support How Does The Use Of Alliteration In Poems Support The Theme?

How does the use of alliteration in poems support the theme? - poems of support

Increases in the poem "the tide, the tide Falls" by Longfellow,

"Until the flood, the wind dies
The darkness of dusk, the curlew calls;
On the beach promenade, wet sand and brown
The traveler hastens to the town,
And flow, ebb.

The darkness is mounted in ceilings and walls,
But calls for the sea, the sea in the darkness;
Small waves, the hands soft, white,
Remove traces in the sand
And flow, ebb.

It breaks the morning the horses in the stable
Seal and neighbors, the groom calls;
The day there, but never
If the travelers to the coast
And flow, ebb. "

How Alliteration support the theme, like nature in motion, regardless of the killing of people? I am lost in this area. please help? And if you do not mind, identify some of the alliteration? I want to see if I was right.

Thank you.