What trick is played at the circus?

One of the circus performers disguised himself as a drunk and made a deal with the ringmaster to let him ride. The ringmaster had no idea it was one of his own people until the man shed 17 layers of clothing and rode one of the horses standing up.

"So, then, the ringmaster he made a little speech, and said he hoped there wouldn't be no disturbance, and if the man would promise he wouldn't make no more trouble he would let him ride if he thought he could stay on the horse. So everybody laughed and said all right, and the man got on.

The minute he was on, the horse begun to rip and tear and jump and cavort around, with two circus men hanging on to his bridle trying to hold him, and the drunk man hanging on to his neck, and his heels flying in the air every jump, and the whole crowd of people standing up shouting and laughing till tears rolled down. And at last, sure enough, all the circus men could do, the horse broke loose, and away he went like the very nation, round and round the ring, with that sot laying down on him and hanging to his neck, with first one leg hanging most to the ground on one side, and then t'other one on t'other side, and the people just crazy. It warn't funny to me, though; I was all of a tremble to see his danger. But pretty soon he struggled up astraddle and grabbed the bridle, a-reeling this way and that; and the next minute he sprung up and dropped the bridle and stood! and the horse a-going like a house afire too. He just stood up there, a-sailing around as easy and comfortable as if he warn't ever drunk in his life -- and then he begun to pull off his clothes and sling them. He shed them so thick they kind of clogged up the air, and altogether he shed seventeen suits. And, then, there he was, slim and handsome, and dressed the gaudiest and prettiest you ever saw, and he lit into that horse with his whip and made him fairly hum -- and finally skipped off, and made his bow and danced off to the dressing-room, and everybody just a-howling with pleasure and astonishment.

Then the ringmaster he see how he had been fooled, and he was the sickest ringmaster you ever see, I reckon. Why, it was one of his own men! He had got up that joke all out of his own head, and never let on to nobody."