Then we see the huge harvesting machines driven by powerful tractors or pulled by four or five horses abreast.

然后我们看到巨大的收获机器由强大的拖拉机驱动，或由四匹或五匹马并排拉动。

To keep its internal mechanics synchronized, it used a 50-foot shaft running right through the machine driven by a five horsepower motor.

为了保持内部机械装置同步，它用了个 50 英尺长的传动轴， 传动轴由一个 5 马力功率的电机驱动。