Biggest wheel on earth 240 ft. diam. with heaviest axle ever forged (56 tons), World's Fair, St.Louis, U.S.A.
Scan by NYPL
<a rel="nofollow" class="external free" href="https://digitalcollections.nypl.org/items/510d47e0-93da-a3d9-e040-e00a18064a99">https://digitalcollections.nypl.org/items/510d47e0-93da-a3d9-e040-e00a18064a99</a>