“…For the most part, speculation has driven discussion for well over 100 years (e.g., Ford and Webb, 1956;Goldstein, 2004;Henderson, 1872;Henshaw 1885;Moorehead, 1900;Peabody, 1901;Pennypacker, 1938;Webb, 1968;Yates, 1889Yates, , 1890. One the one hand, the morphology of a plummet generally matches what is commonly recognized as a plumb bob: "a weight with a pointed tip on the bottom that is suspended from a string and used as a reference line that is perpendicular to the ground."…”