During the Construction
During the construction of the Eiffel Tower, the uprights were placed on concrete foundations installed a couple of meters below-level on top of a layer of compacted gravel. Each corner rests on its own block support, applying a pressure of approximately 3 to 4 kilograms per square centimetre, and at the same time, each block is joined to the others by walls. The Eiffel Tower was assembled using wooden scaffolding and small steam cranes that were mounted onto the tower itself. The first level was completed thanks to the use of twelve temporary wooden scaffolds, that were 30 metershigh, and four larger scaffolds of 40 meterseach. On December 1887, the joining of the major girders up to the first level was completed.