On the point of an upright needle he laid horizontally a fine steel bar, which could turn to the right and left like the magnetic needle in a compass-box..
他在一根垂直的针头顶点，设置了一根水平的钢制细棍，它可以左右转动，就像罗盘里的磁针那样。
2
Don't forget to put in a compass when you load the box for expedition.