While "The Loves of the Plants" celebrates the natural world and advances several scientific hypotheses regarding the formation of the cosmos, the moon and the earth, "The Economy of Vegetation" celebrates scientific progress and technological innovation, such as the forging of steel, the invention of the steam engine and the improvements to gunpowder. It depicts scientists and inventors, such as Benjamin Franklin, responsible for this progress as the heroes of a new age; he “mythologizes” them. The poem at some points goes further, into what would now be called science fiction, forecasting that the British Empire will have giant steam-powered airships ("The flying-chariot through the fields of air. Fair crews triumphant, leaning from above") and far-ranging submarines ("Britain's sons shall guide | Huge sea-balloons beneath the tossing tide; The diving castles, roof'd with spheric glass, Ribb'd with strong oak, and barr'd with bolts of brass, Buoy'd with pure air shall endless tracks pursue").