As if to dismiss that as too simple a challenge, according to press reports of the day, he then flew under at least three other, much lower, bridges - London Bridge, Blackfriars and Waterloo - before stepping ashore at Westminster to be greeted by a cheering crowd who had gathered to meet a dignitary expected by boat from Paris.

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Long, skinny tourist boats, reminiscent of those in Paris, execute precarious three-point turns as they inch under the low bridges.

FORBES: Playing the Float

In total, the process will require three weeks of multi-state trips at speeds as low as 5 miles per hour, weaving through traffic, negotiating bridges and weaving around red tape.

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