It was a small vacuum chamber, about the size and shape of a bathtub stopper, that contained a plunger and spring, and had two small air hoses attached to it.
它是一款非常小巧的真空管，形状和大小如浴缸塞，内含一个柱塞和弹簧，由两个小型空气软管连接。
2
Both systems use the spring or plunger instability against its counterpart to create the bias effect.
两种系统都使用弹簧或顶针相对于其配对体的不稳定性来形成偏置效果。
3
The spring eventually caused the plunger to rise, and moved the switch to the “on” position. The wipers wiped.