The log indicated a mean speed of between eight and nine miles.

经常被抛下水去测量航速的测程器指出航行的平均时速是八海里至九海里。

There my eyes fell on the compass. Our heading was still northerly. The log indicated a moderate speed, the pressure gauge a depth of about sixty feet.

到客厅中，我的眼睛就盯在罗盘上面。我们的方向总是往北。测程器指的是平常的速度，压力表指出船在六十米左右深的水层。