pamphlet. 3 text figures. 4 pages (pp. 6-9.) IN: Archives of the Roentgen Ray, Vol. 18, No. 155 . Tall 8vo, original printed wrappers. London: Rebman, June 1913. Whole Number offered entire. very good.
"Bucky devised a diaphragm for roentgenography which, by preventing the secondary rays from reaching the plate, secured better contrast and definition". GM 2691.