These are Thaxter type four lens spectacle frames in aluminum case. The lens frames are D type and the arms are double turn pin with heart shaped ends. The patent on this type of spectacles was taken out on June 18 1839 by Daniel Thaxter of Hingham Massachusetts USA. Daniel and Joseph B. Thaxter were opticians in Boston with a shop at No. 9 Bromfield Street. They manufactured and dealt with a large variety of optical items such as telescopes, and microscopes opera-glasses, spy-glasses spectacles and eye-glasses. They also retailed thermometers, barometers, and other measuring apparatus. The frames are in excellent condition.