The Roux, Combaluzier et Lepape lifts during construction. Equipping the Tower with adequate and safe passenger lifts was a major concern of the government commission overseeing the Exposition. Although some visitors could be expected to climb to the first or even the second stage, the main means of ascent clearly had to be lifts. Constructing lifts to reach the first platform was relatively straightforward: the legs of the lower section were wide enough and so nearly straight that they could contain a straight track, and a contract was given to the French company Roux, Combaluzier and Lepape for two lifts to be fitted in the east and west legs. Roux, Combaluzier and Lepape used a pair of endless chains with rigid, articulated links to which the car was attached. Lead weights on some links of the chains' upper or return sections counterbalanced most of the car's weight. The car was pushed up by the links below, not drawn by those above: to prevent the chain buckling it was enclosed in a conduit. At the bottom of the run the chains passed around 12 foot 10 inch diameter sprockets. Smaller sprockets at the top guided the chains. No photographer credit.