Cyclometricus est liber mathematicus scriptus a Willebrordo Snellio anno 1621. In hoc libro, Snellius tractat de geometria circulorum, et explicat methodos cyclometricas ad mensurandum circumferentias et arcus circulorum. Praeterea, in Cyclometrico, Snellius introducit trigonometriam sphaericam, quae est ramus trigonometriae quae tractat de triangulis in superficie sphaerica. Hoc opus magnum est in historia mathematicae, et Snellius est consideratus unus ex primis mathematicis Hollandiae.This scarce antiquarian book is a facsimile reprint of the old original and may contain some imperfections such as library marks and notations. Because we believe this work is culturally important, we have made it available as part of our commitment for protecting, preserving, and promoting the world's literature in affordable, high quality, modern editions, that are true to their original work.