Recently a man came to the writer and wanted a hole put through the center of some marbles. The accompanying sketch gives an idea of the way the work was accomplished. Through a piece of soft steel 2 x 3 x 1 inches a hole was drilled of the size of the one wanted in the marbles. Then with a countersink a conical aperture was made in one side as illustrated. Two tapped holes, one above the other, below the aperture, admitted a pair of thumbscrews that secured a flexible strip made from the spring of an eight-day clock. On the strip next to the marble which was seated in the conical aperture a piece of emery cloth was placed. The whole was then held in the vise and the marble was easily bored.

Figs. 108 and 109 - A method of drilling holes in marbles.