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.
According to our research of Georgia and other state lists there were 18 registered sex offenders living in Hull, Georgia as of March 07, 2017. The ratio of number of residents in Hull to the number of sex offenders is 11 to 1. Nearest city with pop. 50,000+: Athens-Clarke County, GA (6.5 miles , pop. 100,266).