He would rather be a plumber's mate and do a real job that requires doing than learning about hydrostatics sitting at a desk, without understanding what practical use they are going to be.

他宁愿做一个水管工的伙伴，做一份真正需要动手的工作，也不愿坐在桌子前学习流体静力学，而不知道这些东西有什么实际用途。