Rhyme is a Likeness or Uniformity of Sound in the terminations of two Words, I say, of Sound, not of Letters; for the Office of Rhyme being to content and please the Ear, and not the Eye, the Sound only is to be regarded, not the Writing: Thus Maid and Perswade, Laugh and Quaff, tho' they differ in Writing, rhyme very well: But Plough and Cough, tho' written alike, rhyme not at all.
In our Versification we may observe 3 several sorts of Rhyme; Single, Double, and Treble.
The single Rhyme is of two sorts: One of the Words that are accented on the last Syllable: Another, of those that have their Accent on the last save two.
The Words accented on the last Syllable, if they end in a Consonant, or mute E, oblige the Rhyme to begin at the vowel that precedes their last Consonant, and to continue to the end of the Word: In a Consonant; as,
Here might be seen that Beauty, Wealth, and Wit,
And Prowess, to the Pow'r of Love submit.Dryd.
In mute E; as,
A Spark of Virtue by the deepest Shade
Of sad Adversity, is fairer made.Wall.
But if a Diphthong precede the last Consonant, the Rhyme must begin at that Vowel of it whose Sound most prevails; as,
Next to the Pow'r of waking Tempests cease,
Was in that Storm to have so calm a Peace. Wall.
If the Words accented on the last Syllable end in any of the Vowels except mute E, or in a Diphthong, the Rhyme is made only to that Vowel or Diphthong. To the Vowel; as