Caption for Figure 2, which depicts the old Conntecting Terminal Elevator (made out of iron and wood in 1882, not the one made out of reinforced concrete and built to replace the first one in 1914).
“An Old Timer at C.T.T. elevator, Buffalo, NY.” Unloading grain at the Connecting Terminal Elevator, designed and built by Robert Dunbar. The elevator leg that has been lowered down into the storage compartment of the “old time” steam-powered, wood-hulled vessel owned by the Lackawanna Green Bay Line is part of the world’s first mobile marine tower. Its height can be suggested by the great height of the marine tower(s) at the neighboring structure, which is in fact the Marine Elevator (originally built 1848, burned 1879 and rebuilt in 1884). Note as well the congestion of the harbor and the various sizes of the vessels competing for access to the wharves.
Courtesy the Library of Congress, Prints & Photographs Division, Detroit Publishing Company.
The mobile marine tower, also known as a "loose leg," was invented in 1882 by Robert Dunbar, the same engineer who had designed the Dart Elevator back in 1843. Originally powered by steam engines, loose legs became very popular after the electrification of power at the end of the 19th century. A tall building set atop wheels, the loose leg was originally a solution to the overcrowding of Buffalo's harbor. The idea was that, instead of moving the grain-bearing vessel closer to the grain-elevating "leg," the leg could be moved closer to the vessel.
The same idea had been used in the construction of the floating grain elevator, which was an elevator leg installed on a tug-boat that could be pushed or pulled into position between a ship in need of being unloaded of its cargo and a boat that was waiting to be loaded up. First used in the late 1840s, the floaters became widely used in the 1860s and 1870s in ports such as New York, Buffalo and New Orleans.
Below: both elevators as depicted in Buffalo's Waterfront, by Leary & Sholes (Arcadia, 1981), p. 28: