But the so-called Massachusetts pump invented in USA in 1818 with straight radial blades, semi-open double suction impeller and volute is more close to the modern centrifugal pump.

• 但更接近于现代离心泵的，则是1818年在美国出现的具有径向直叶片、半开式双吸叶轮和蜗壳的所谓马萨诸塞泵。