Passage
For most of history, the height of a building was limited by its walls. In traditional construction, thick stone or brick walls carried the weight of everything above, so a taller structure needed an ever-heavier base. Beyond a certain point, the lowest walls grew so massive that adding floors became impractical.
Two inventions removed the ceiling on height. [A] Engineers began framing buildings with rigid steel skeletons that bore the load instead of the walls. [B] Freed from carrying weight, exterior walls could become thin curtains of glass and stone. [C] Meanwhile, the safety elevator made the upper floors reachable and even desirable. [D] What had once been an exhausting climb turned into a brief, comfortable ride.
These towers reshaped cities. By stacking offices and apartments upward, they packed far more activity onto costly downtown land. Their silhouettes became symbols of ambition and commerce, and the race to build higher pushed engineers to solve new problems of wind, foundations, and fire. The modern skyline, crowded with tall buildings, is the visible result of a quiet revolution in how weight is carried.