TY - JOUR T1 - Experiments on a Fundamental Question in Electro-Optics: Reduction of Relative Retardations to Absolute JF - Proceedings of the Royal Society of London (1854-1905) VL - 55 SP - 252 EP - 265 PY - 1894/01/01/ UR - http://dx.doi.org/10.1098/rspl.1894.0040 M3 - doi:10.1098/rspl.1894.0040 AU - Kerr, J. ER -