TY - JOUR T1 - On an Easy and at the Same Time Accurate Method of Determining the Ratio of the Dispersions of Glasses Intended for Objectives JF - Proceedings of the Royal Society of London (1854-1905) VL - 27 SP - 485 EP - 494 PY - 1878/01/01/ UR - http://dx.doi.org/10.1098/rspl.1878.0088 M3 - doi:10.1098/rspl.1878.0088 AU - Stokes, G. ER -