Arrows and Threads

From Inventions

Historic Period

sec. V-VI d.C.

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Description

Method probably derived from the gromatic tradition mentioned by G. D'Aurillac (972-1003, III, 26) and L. Fibonacci (1220, VII, p. 202). Two arrows, each tied to a rope, are shot to the top and the base of a tower, whose height is determined by applying the Pythagorean theory after having measured the two ropes, which represent the hypotenuse and cathetus of a right triangle whose other cathetus consists of the tower.

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Bibliographical Resources

Fibonacci, Leonardo. La Pratica di Geometria. Volgarizzata da Cristofano di Gherardo di Dino cittadino Pisano,dal codice 2186 della Biblioteca Riccardiana di Firenze, a cura e con introduzione di Gino Arrighi. Pisa, Domus Galileiana, 1966, VII, p. 202.

Papa Silvestro II. Geometria incerti auctoris, in Gerberti postea Silvestri II papae Opera matematica, (972-1003). Hildesheim, Georg Olms Verlagsbuchhandlung, 1963, 8.

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Author of the entry: Filippo Camerota