The drawing below is from Gustave Eiffel's book describing the tower that bears his name. There are 53 of them in total.
IX. Lower part. Generalities and details
With the board 9 one enters quite far in the technical detail. This board describes a large number of elements, that's why it seems "fuzzy". But on closer inspection we see that it describes the junctions between the rafters and the section beams or the spacers, as well as the gussets, (flat pieces from which stem reinforcements). There is also a pretty impressive drawing of the vertical projection of the first floor. This drawing was probably very complex to do.
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