There was a stairway outside the house, which led up to the rear part of the second story. One day Henry was sent on an errand, and he took a tin bucket along. I knew he would have to ascend those stairs, so I went up and locked the door on the inside, and came down into the garden, which had been newly ploughed and was rich in choice firm clods of black mold. I gathered a generous equipment of these, and ambushed him. I waited till he had climbed the stairs and was near the landing and couldn't escape. Then I bombarded him with clods, which he warded off with his tin bucket the best he could, but without much success, for I was a good marksman. The clods smashing against the weather-boarding fetched my mother out to see what was the matter, and I tried to explain that I was amusing Henry. Both of them were after me in a minute, but I knew the way over that high board fence and escaped for that time. After an hour or two, when I ventured back, there was no one around and I thought the incident was closed. But it was not. Henry was ambushing me. With an unusually competent aim for him, he landed a stone on the side of my head which raised a bump there that felt like the Matterhorn. I carried it to my mother straightway for sympathy, but she was not strongly moved. It seemed to be her idea that incidents like this would eventually reform me if I harvested enough of them. So the matter was only educational. I had had a sterner view of it than that, before. It was not right to give the cat the "Pain-Killer"; I realize it now. I would not repeat it in these days. But in those "Tom Sawyer" days it was a great and sincere satisfaction to me to see Peter perform under its influence--and if actions _do_ speak as loud as words, he took as much interest in it as I did. It was a most detestable medicine, Perry Davis's Pain-Killer. Mr. Pavey's negro man, who was a person of good judgment and considerable curiosity, wanted to sample it, and I let him. It was his opinion that it was made of hell-fire.