That's because not every single line is perfect iambic pentameter. Line after line of perfect meter ends up sounding more like a nursery rhyme than poetry, so poets (and playwrights) will play with the meter to emphasize certain words. Let's skip back to one of the non-perfect lines in the Prologue:
Hull is a town in Plymouth County, Massachusetts, United States, located on a peninsula at the southern edge of Boston Harbor. Its population was 10,293 at the 2010 census. Hull is the smallest town by land area in Plymouth County and the fourth smallest in the state.
Hull, TX-Peer Comparisons by Rank and Percentile. The table below compares Hull to the other 1,752 incorporated cities, towns and CDPs in Texas by rank and percentile using July 1, 2015 data. The location Ranked # 1 has the highest value. A location that ranks higher than 75% of its peers would be in the 75th percentile of the peer group.