“This is a design for a portable polariscope. A polariscope is a useful tool for viewing stress in transparent materials such as glass or plastic. Using either linear or circular polarization, stress in glass is visible through the polariscope viewfinder. It is a useful teaching tool for understanding the properties of glass or plastics, and a necessity in the glassblowing studio to aid in the fabrication, quality control and troubleshooting of glass work.”
Resource submitted by Amy Lemaire