An aqueduct is likea bridge for boats. When they built the Erie Canal, they didn't want itto run into other canals and rivers. Aqueducts have water that runs acrossit so boats can flow right over them. The biggest aqueduct had to crossthe Mohawk River at Crescent. They had to make it nearly 2,000 feet longjust to cross the river!

Locks can raise orlower boats to a different level. When a boat drives into a lock, the doorsclose and shut it in. Once the boat is in, the water either fills up, ordrains out to put the boats at a different heights. The water in the ErieCanal isn't all the same height. If there were no locks, the boats wouldjust fall in holes. One of the biggest obstacles was a 66 foot mountainof rock! Engineers had to make 5 locks in a row to climb the 66 feet!

A towpath is wherethey horses and mules used to pull the boats. They made towpaths becausethe boats didn't have motors and they needed mules to pull the boats. Themules couldn't walk in the water, so the towpaths are on the side. Thetowpaths are still by the canal today, but no mules have to walk on them!The animals had harnesses that went on their backs. There was a cord thatconnects the harness to the boat.