American Falls and Steel Arch Bridge from Luna Island, Niagara Falls

"American Falls properly comprises two precipitating floods, for the stream as it approaches the fearful brink, is divided by Luna Island and goes tumbling with increased velocity over the ledge at Centre Fall, on one side, and American Fall on the other.  At the point shown, the sheer descent is one hundred and fifty-nine feet, and the width is eleven hundred feet.  The amount of water thus precipitated is computed to be two million five hundred thousand gallons per second."

Not sure of the exact date on this unsent postcard of Niagara Falls.