TY - JOUR T1 - On the Measurement of the Chemical Brightness of Various Portions of the Sun's Disc JF - Proceedings of the Royal Society of London (1854-1905) VL - 12 SP - 648 EP - 650 PY - 1862/01/01/ UR - http://dx.doi.org/10.1098/rspl.1862.0140 M3 - doi:10.1098/rspl.1862.0140 AU - Roscoe, H. ER -