By this phrase we are meant to understand that Sir John handles the politics, while the chief engineer handles the engineering aspects of colonialism. But there is a second meaning, relating to the two political forces that will be portrayed in the novel: Unionism and Separatism, the forces that alternately build and pull apart states. When we get to know the chief engineer better in Part Three, we find that he is the ultimate Separatist, an expert at dividing or blasting apart any group. This contrasts with Sir John, who is clearly engaged in economic empire-building. The point here, however, is that the two forces work hand in hand for colonialism, which must blast apart existing states and structures in order to build its own.