Arrows and Threads
From Inventions
Historic Period
5th-6th cent. A.D.
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.
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.
Author of the entry: Filippo Camerota