798. If it were severe, they all fell.

如果地震剧烈，所有的木棒都会例下。

799. Thus the rods, by falling, and by the direction in which they fell, recorded for the slumbering scientist the strength of a shock that was too weak to waken him, and the direction from which it came.

由于地震太弱而未惊醒科学家时，木棒倒下的多少和倒下的方向就为科学家记录下了地震的强度和地震方向。

800. But instruments far more deliecate than that were needed if any really serious advance was to be made.

但是，如果要取得真正重大的进展，需要有比这种装置精细得多的仪器。

801. The ideal to be aimed at was to devise an instrument that could record with a pen on paper, the movements of the ground or of the table as the quake passed by.

理想的目标是设计出这样一种仪器：当地震发生时，它能用笔在纸上记录下大地和桌子运动情况。