Measuring the diameter of a sphere

by Ray Hill

Ever tried to measure the diameter of a sphere? I found it wasn't easy. When we started offering stone eggs and spheres it was a task trying to determine the exact diameter of the spheres. I tried taking a ruler and holding it on top of the sphere and could only guess at the reading on the ruler. I even wrapped a string around what I thought was the center of the sphere to get the circumference, then divide the measurement by 3.1416 or pi (A close number!), to get the diameter. This method was cumbersome and not all that accurate. Then I figured out how to make me a wooden jig to measure spheres. It makes short work of measuring the diameter of a sphere, fairly accurate anyway. We've been using this jig for a few years now. You may not have a lot of different size spheres to measure the diameter of, but if you do, this method works reasonably well.

You are welcome to copy this idea.

Happy rock hunting.

Ray Hill
Great South Gems & Minerals, Inc.
www.greatsouth.net
888-933-GEMS

Note: Only rock clubs have permission to print this article but must give credit to the author, Ray Hill, and Great South Gems & Minerals, Inc. For everyone else, please email us for permission.

Great South Gems & Minerals, Inc. www.greatsouth.net 38 Bond Drive Ellenwood, Georgia 30294 USA 1-888-933-GEMS (4367) FAX: 770-389-8095