Plumbing Depths

As the elevator industry strove, over the centuries, to build and to service ever-higher structures, a corresponding goal was to make it possible to move materials and individuals between the surface and ever-deeper levels. The "Genesis of Lifting" Wing bore out that ore might have been more important than human welfare in the Copper, Bronze and Iron Ages. The watershed invention of, and improvements upon, the steam engine was by entrepreneurs attempting to make lower levels of mining more productive -- not moving goods or individuals above the surface. Inventors focused upon underground transportation also perfected the car safety, traction sheave and wire rope. Previous Galleries presented information concerning the growth of commerce within and between cities. As urban centers became more congested, and ground more expensive, commercial establishments were compelled to create more space for storage and equipment. Very often it was more economical, secure and efficient to dig out a basement than to add a story. And a cellar was closer to such city utilities as existed. Supplies could more easily be unloaded directly into basements than upper stories. This was the level that held fuel and furnace, residue ashes, cooled barrels of beer and the simple lifts that moved materials -- some better left unseen by customers -- from cellar to surface. Centuries later, the single cellar would give way to two or more sub-basements, service levels for high-rise buildings. The most efficient of these lower levels received freight via heavy-duty truck elevators in a move to reduce off-street unloading. Plans to build the London "Underground" brought the realization that trains would discharge passengers in numbers previously not experienced -- one after another. Subway rail transportation had become efficient in moving masses of people; how could they be brought to the surface as fast? The elevator industry's moving stairway was the answer. As it was improved, the escalator became accepted as the sister piece of equipment to the underground railway.