"Here, John." The demon unbuttoned his coat and reached into his pants pocket, but father shook his head.
"No tip. Happy just to look at horseless."
The demon stopped and studied Father as you might look at a dog that had suddenly said he was going to the opera. "Well, I'll be damned," he said. He reached into a pocket of his waistcoat and took out a card, and handed it to Father with a flourish. "I can use honest handymen like you. You come around anytime, you sabe me?" (4.45-47)
Windrider demonstrates his earnest fascination with machines and his willingness to help beyond financial gain. This ends up coming in handy, too, when he finds work with Mr. Alger.