Show asphalt much used in building roofing c constitutes nn an important branch of a much broader field of engineering known as waterproofing in which asphalt lias has for thousands ot of vears played nn an important part the ancient Egypt egyptians inns were able to preserve their mummies in good condition to the present day by wrapping them in fabric saturated and made waterproof and weather resisting sting with as ahalt modern ingenuity has discovered no material better adapted to waterproofing waterproof ink and preserving its present day structures than asphalt it Is not surprising therefore that in recent yea years rs the production of in large quantities has been rendered possible by refining crude petroleum P Rr oleum its use for roofing and waterproofing ila has deve developed I 1 aped rapid rapidly ay in ninny many structures tures from root roof to cellar asphalt plays a I 1 an n important part first as roofing then as sheathing and insulating and finally as a mem membrain braim for the underground under round rj und portion port ign exchange e |