The drawing below is from Gustave Eiffel's book describing the tower that bears his name. There are 53 of them in total.
XXXVI. General layout of distribution apparatus (overall plan)
This board is the continuation of the previous one, the XXXVe. It represents the elevator Fives-Lille in detail. it is a fairly complex board in the margin of the Eiffel Tower since it is not a structural element of the tower.