This project was originally published in the January 2001 issue of Popular Mechanics. You can find more great projects at Popular Mechanics DIY Central.
Step 1: Ruler Selection & Marking
Step 2: Basic Measurement
Step 3: Measuring Circles
Step 4: Middle Marking and Finding Center
A similar method is used to find the board’s center. Angle a ruler across the board’s width so that a whole number on the ruler is at each edge of the workpiece. Find the midway point between the two numbers, and mark there (Photo 2). With either method, it doesn’t matter if you place the end of the ruler at the board’s edge or if you use the middle of the ruler.