The drawing below is from Gustave Eiffel's book describing the tower that bears his name. There are 53 of them in total.
XXXVII. (Elevations) and switchgear of the distribution
Another complete board dedicated to the Fives-Lille lift of the Eiffel Tower. It is like the previous ones of quite complex technical data which explains the precise forms and the settlements of the different elements of the pumps and the systems of elevation.
See also: