Floating coal elevator. Designed and constructed by James Rigg, a British engineer from Chester. It consists of a wide platform on two floating cylinders, which supports a steam engine that generates the necessary movement to the chains and pulleys. In the center, a tower serves as a regulator and mechanical balance. The elevator extends from the deck of the ship to the pontoon by means of the aforementioned tower. Moving buckets, driven by the steam engine, pick up the cargo from the pontoon and throw it, after being automatically weighed, into the ship's coal compartments or warehouses. Engraving by Tomas Carlos Capuz (1834-1899). La Ilustracion Espanola y Americana (The Spanish and American Illustration), 15 January 1883.