The drawing below is from Gustave Eiffel's book describing the tower that bears his name. There are 53 of them in total.
XIV. Panel 29 and third floor
Another board describing an 'assembly detail'. Here, Gustave Eiffel describes the techniques to assemble the upper part of his tower. It shows the description of the beam of the third floor, the one that supports the pulleys of the elevator, as well as the entire gallery of the 3rd floor. There is even, above the third floor, a room reserved for the engineer. The left part of this plate gives the dimensions of various beams of this upper part, as well as the description of the railing, etc.
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