During this short time the mirror moves, though but little, and in it the exit-spark is seen as if it had moved aside from the entrance-spark.

在这极短的时间内，镜子是转动的，而且因为转动的间隔很短暂，所以看上去仿佛那个“出端火花”是从“入端火花”的位置移动出来的。

youdao

During this short time the mirror moves, though but little, and in it the exit-spark is seen as if it had moved aside from the entrance-spark.

在这极短的时间内，镜子是转动的，而且因为转动的间隔很短暂，所以看上去仿佛那个“出端火花”是从“入端火花”的位置移动出来的。

youdao