sentences:  On top of these sills were laid 4-by-6-inch or 4-by-8-inch oak "stringers" notched and pinned together.The rails were flat iron straps (section of rail) 12 to 15 feet long, two-and-a-half inches wide, and only five-eighths of an inch thick.Spikes held them onto the stringers, and their ends were mitered.