Ampule goniometers differ in the way they measure angles
Ampule goniometer, metal, circa 1900
Ampule goniometers differ in the way they measure angles:
- a more massive protractor does not have a vernier scale, the angles are counted using a scale on a glass ampule (10 divisions) with a division angle of 0.1 degrees;
- a less massive goniometer has a vernier scale with a division price of 0.1 degrees