Abstract Photocopy of his paper concerning his father, Ardon Herman of Brinsmade, N.D., who invented and developed a disk designed to lessen breakage of disk blades from rocks when tilling fields. It was later manufactured by Summers Manufacturing, Devils Lake, N.D. Includes an explanation of the problem with the old design of disks, the development of a prototype, and its solution using the diamond disk. Includes mention of Ardon Herman's method of building his prototype. Also includes a chart...