There is a story about an inventor who approached Trajan[0] with plans for new construction machinery that would require far fewer laborers. Trajan's response w

There is a story about an inventor who approached Trajan[0] with plans for new construction machinery that would require far fewer laborers. Trajan's response was incredulous: if he used the new construction equipment, how did he expect he would manage to pay everyone? I.e. the construction project was itself a beneficium to those it employed. [0] Could be another emperor -- I just have an association of this story with Trajan's markets for some reason.