Existing comment:
First American Macadam Road:
National Road workmen, often wearing goggles to protect their eyes, pounded stones into pieces with small hammers. Inspectors passed each stone through a three-inch ring to assure proper size. Other workers raked the stones level in three layers on a prepared roadbed. The surface was rolled smooth with a cast-iron roller. The top layer, cemented with rain water, became as hard as concrete. |