Alexander Pope emended the word sound (line 5) to south.
A discussion of Pope's motive for this emendation is discussed here:
... 6.7% from 18 to 24, 33.6% from 25 to 44, 20.6% from 45 to 64, and 9.6% who are 65 years of age or older. The median age is 35 years. For every 100 females there are ...