1. The fourth time he fell into the hands of a professional slave-catcher, who promptly had the man´s foot cut off with an axe against a tree stump.
    第四次逃跑时，他落到了一个职业奴隶捕手的手上。那人立即用斧头将他的一只脚放在树桩上砍了下来。

2. He stumbled over a stump.
    他在树桩上绊了一下。

3. It was five feet ten inches in diameter near the stump, and four feet eleven inches in diameter at the end of twenty-two feet, after which it lessened a little, and then parted into branches.
    根部附近直径是五英尺十英寸。树干二十二英尺处，直径为四英尺十一英寸。然后渐渐地变细，分出了枝桠。