In the pale blue dot by carl sagan what did his grandfather lieb transport across the river bug

In the Pale Blue Dot by Carl Sagan, Lieb, his grandfather, the only job he could get as a young man was to transport people across the nearby river Bug. The customer would mount on his back in order to be delivered to the other side of the river. Some times the water reached his waist.

answer; engram;

answer; posthypnotic;