Alexander Pope emended the word sound (line 5) to south.
A discussion of Pope's motive for this emendation is discussed here:
... to the United States Census Bureau, the town has a total area of 5.8 km² (2.2 mi²). 5.4 km² (2.1 mi²) of it is land and 0.3 km² (0.1 mi²) ...