My wife is a funambulist. I first caught her at it in the park. In between two trees. The look of concentration on her face was entrancing. The way she used her feet, the grace of her movement, just captivating.
I know now, that it's called a slackwire, and that the key is the performer being in tune, and moving with, the wire. Of course it came to an abrupt end that day. She hadn't checked her laces before starting and one had worked its way loose. She delicately began to lift her right foot, only to find the lace from that boot was trapped under her left foot. Her balance gone, down she went.
Only about a foot of course, it was a slackwire, not a highwire. I ran over to check she was ok. Only her pride was hurt. As she stood up I remember noticing that even stationary, on flat ground, she was quite the most graceful thing I had ever seen.