15. If he did not do this work himself, he had it done by a "hoof-shaper," his name for a blacksmith, and this man had to be able to "tack iron on everything that flew past" if he was on to his business.

Ans: If he did not do this work himself, a "hoof-shaper", his name for a blacksmith, did it for him, and this man had to be able to "tack iron on everything that flew past" if he was on to his business.