IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. This clear plastic semicircular ...

This German silver protractor is in the shape of a quarter-circle. It is divided by half-degrees and marked by tens from 0° to 90°. Flat bars extend on both sides of the protractor. A movable arm ...

To no one’s surprise, those clear plastic protractors we were all taught to use in grade school are far from being the most accurate way to measure an angle. They’re perfect for a grade five homework ...