The Taber Torsional Stiffness Apparatus Model 108 is used  to measure the flexibility and stiffness of leather and similar materials.  A specimen is affixed to a weighted clamp secured at the bottom of a torsion wire.  A torsion head equipped with a dial protractor is turned in a plane normal to the torsion wire until the specimen has been twisted 90 degrees.  The angle of torsion reading is obtained from the dial protractor.