Man needs but add his labor to the great mass of clays--firebrick, or vitrified brick--is the ideal road surface.
(Man; needs; ) (Man; add; his labor; to the great mass of clays) (add his labor to the great mass of clays; is; the ideal road surface)
Man Man add his labor to the great mass of clays
needs add is
his labor to the great mass of clays
the ideal road surface