Fore-shadowing

"...Its massive oak shaft and polished horn-beam cogs have long since passed away, and yielded to their successor, cast iron, which in its turn is now being rapidly replaced by the stronger metal, steel, thus keeping up that ever-changing cycle of advancement in the arts which is carrying us forward to discoveries that may change every phase of civilized life, if the exhaustion of our coal does not land us again into a state of barbarism." Bessemer(1872).  Italics mine.