Section 10
SEC. 10. All material used shall be of good quality and adapted to the conditions of the country. The rails shall be steel rails weighing fifteen kilograms per meter with a resistance of three thousand five hundred kilos. On each kilometer of track there shall be used at least twelve hundred ties of native hard wood, one meter and fifty centimeters long, seven inches wide and five inches thick. The track of the railways shall be of the gauge of at least seventy-five centimeters. The bridges, culverts, and buildings shall be of masonry and steel, but with the authorization of the Secretary of Commerce and Communications, provisional structures of wood may be erected.