# Polar Curve French Curves

## Description

A Polar Spiral French curve, or irregular curve, is used to draw engineering diagrams and steam curves, and is plotted by using the polar equation.

## Keywords

curve ruler, curve rulers, curved ruler, Polar Curve French Curves, Polar Curve Irregular Curve, polar curve ruler, polar equation, Ruler, rulers

## Galleries

## Source:

French, Thomas E *A Manual of Engineering Drawing for Students and Draftsmen* (New York, NY: McGraw-Hill, 1911)

Courtesy the private collection of Roy Winkelman