Page:Historic highways of America (Volume 13).djvu/211

 adopted for the road, and was in all cases laid to form horizontal arcs of circles, or their tangents. Flat iron bars on wooden rails were placed on the inclined planes. On the balance of the road, edge rails 18 feet in length, weighing 39½ pounds to the yard were laid, resting in iron chairs on wooden sills. The latter were fastened to cross ties where the road passed over high embankments, but, on solid ground they were attached to stone blocks measuring about 3½ cubic feet. To do this two holes were drilled into each block. Into these holes oak plugs were driven. The cast-iron chair was placed directly upon the top of the stone block, and spikes driven through holes in the flanges of the chair into the oak plugs. The rail was a double headed rail, and held in place by a wedge. The difficulty of the spreading of the tracks was at first overcome by substituting for each alternate pair of blocks a stone block some 7 feet long, extending across the track, and having a chair at each end. This was found to be too expensive, and wooden cross ties were placed between each pair of stone blocks."