He shows them next (but after interval,

  'Twould seem, of many and many an age, not years)

  How through the Alps, a captain out of Gaul,

  To war upon the great Viscontis, steers;

  And seems to straiten Alexandria's wall,

  Girt with his forces, foot and cavaliers:

  A garrison within, an ambuscade

  Without the works, the warlike duke has laid;