Research paper RP1787-RP1788, RP1791-RP1795, RP1797, RP1799-RP1800, RP 1803, RP1805-RP1806. RP 1793. Changes caused in refractivity and density of glass by annealing [with list of references]; by Arthur Q. Tool, Leroy W. Tilton, and James B. Saunders.