The Eclectic Content and Sources of Christopher Clavius's Geometria Practica

TL;DR

This paper analyzes the eclectic sources and unique treatment of practical geometry in Clavius's 1604 textbook, highlighting four sections with distinctive source usage and approach.

Contribution

It uncovers the diverse sources and innovative methods in Clavius's Geometria Practica, especially in four key sections, revealing his eclectic scholarly approach.

Findings

Clavius's use of sources varies across sections.

He employs innovative methods for geometric constructions.

The textbook includes unique algorithms for root calculations.

Abstract

We consider the Geometria Practica of Christopher Clavius, S.J., a suprisingly eclectic and comprehensive textbook of practical geometry, whose first edition appeared in 1604. Our focus is on four particular sections from Books IV and VI where Clavius has either used his sources in an interesting way or where he has been uncharacteristically reticent about them. These include the treatments of Heron's Formula, Archimedes' Measurement of the Circle, four methods for constructing two mean proportionals between two lines, and finally an algorithm for computing nth roots of numbers.