• Niagara as a Timepiece

      Spencer, J.W. (Appletons' Popular Science Monthly, May 1896, pp.1-20., 1896-05)
      The article discusses the history of Niagara Falls, including the narrative of Hennepin in 1697. Also mentioned are the methods of calculating the age of Niagara Falls, "All attempts at reducing geological time to solar years meet with great difficulties, yet Niagara Falls have been used as a chronometer as frequently as any other natural phenomenon, and indeed Niagara is perhaps the best measurer that we have. Andrew Ellicott (in 1790) divided the length of the gorge by the supposed rate of recession of the falls, and assigned fifty-five thousand years as the age of the cataract. Forty years later Bakewell reduced the time to twelve thousand years, and a few years afterward Lyell's estimate of thirty-six thousand years became popular and remained so until about fifteen years ago. This method of dividing the length of the chasm by the rate of recession was correct as far as it went, but even the rate was not then known."