translation.en: He added new linear motion guides to the pistons, he added a condenser to cool the steam outside the cylinder, he made the engine double-acting so it had double the power.
translation.zh: 增加了活塞的直线运动， 增加了冷凝器用以冷凝缸体外的蒸汽， 他制作了双动引擎，从而可以产生两倍的功。