Talk:Proceedings of the Royal Society of London/Volume 60/On the Determination of the Wave-length of Electric Radiation by Diffraction Grating
 | Proceedings of the Royal Society of London/Volume 60/On the Determination of the Wave-length of Electric Radiation by Diffraction Grating was the featured text for April 2015 (discussion). It was considered among the most complete works available on Wikisource. |