An except from Crashing Through, the story of the man who dared to see.
"There's blue stuff on the ground" he said "What is it?"
"That blue shows there's a gas line under the ground." she said.
"Why is it dark on the ground over there? Is that a shadow?"
"No. That's a manhole cover."
May could scarcely believe his luck. These markings on the ground were a fantastic discovery.
"They're everywhere." he said. "Why don't sighted people ever talk about them."