The measures of twelve and fourteen syllables were often mingled by our old poets, sometimes in alternate lines, and sometimes in alternate couplets.
The verse of twelve syllables, called an Alexandrine, is now only used to diversify heroick lines.
Waller was smooth, but Dryden taught to join
The varying verse, the full resounding line,
The long majestick march, and energy divine. Pope.
The pause in the Alexandrine must be at the sixth syllable.
The verse of fourteen syllables is now broken into a soft lyrick measure of verses, consisting alternately of eight syllables and six.
She to receive thy radiant name,
Selects a whiter space. Fenton.
When all shall praise, and ev'ry lay