Germania Ford was nine or ten miles below the right of Lee's line.

Hancock, with the 2d corps, moved by another road, farther east, directly upon Ely's Ford, six miles below Germania, preceded by Gregg's division of cavalry, and followed by the artillery.
Torbert's division of cavalry was left north of the Rapidan, for the time, to picket the river and prevent the enemy from crossing and getting into our rear.

The cavalry seized the two crossings before daylight, drove the enemy's pickets guarding them away, and by six o'clock A.M.had the pontoons laid ready for the crossing of the infantry and artillery.

This was undoubtedly a surprise to Lee.

The fact that the movement was unopposed proves this.
Burnside, with the 9th corps, was left back at Warrenton, guarding the railroad from Bull Run forward to preserve control of it in case our crossing the Rapidan should be long delayed.