Lore: Engineering
Engineering is the applied use of mathematics and the solving of practical problems, often through simple invention. While the more modern notions of engineering apply to mechanical things and artifice, the skill also applies to the understanding of things that are not, but are still marvels of their own by the standards of those eras or those planes. Such includes the Wheel to the Aqueduct, from the Inclined Plane to the Conveyor, and from the Window to the Wall.
Not the confused with the Engineer.