Spirally Designed Picking Tray
Louis S. Kornicker · Micropaleontology · 1957
Since picking microfossils from a sample is a timeconsuming task, any improvement in the efficiency of this operation is of interest to micropaleontologists. The conventional picking tray is rectangular in outline and marked with a grid pattern. The picker moves the tray in one direction until the end of the row is reached, then moves the tray up or down to the next row and proceeds in the opposite direction. The inherent discontinuity of this operation is removed if, instead of a grid, a spiral pattern is employed in a round tray (see text-fig. 1). The picker rotates the tray in one direction (say, counter-clockwise) and, starting from the center, examines or removes the microfossils as they appear between two successive lines of the Archimedean spiral in one continuous operation.