把这一句，留给此刻的你
The height of the pulleys from the ground was twelve yards, and consequently, when the weights had descended through that distance, they had to be wound up again in order to renew the motion of the paddle.
滑车离地面有十二码高，因此，当重物从这段距离下降时，它们必须重新上紧发条，以恢复桨的运动。