Photograph of the aerial transfer bridge (ferry), at Duluth, Minnesota, ca.1920. The bridge stands several stories tall and was built to ferry people from one side of the lake to the other. In the middle of the metal truss bridge, suspended from a moving metal under-carriage, is the ferry car that transports passengers. People can be seen waiting on the right side of the lake, near a building. On the left side of the lake are a few buildings and houses. In the foreground, there is a pier-like walkway.; "Completed in 1905, Duluth's new Aerial Transfer Bridge carried up to 62-1/2 tons including automobiles, horses and wagons, and pedestrian traffic. It took 5 cents and about one minute to transit the 300-foot wide ship canal one way, and a crossing was made about every 5 minutes when demand was heavy. Two 40 horsepower electric motors beneath the suspended car or 'gondola' pulled cables which moved it from side to side while hanging from tracks mounted on the fixed truss overhead. In the event of a power failure, the motorman could hand-power the gondola across the canal." -- unknown author.