Show pipe lines numerous although the public Is seldom conscious of pipe lines they rank second only to the railroads in ton miles of cargo carried there are miles of sewerage pipe lines in north america miles of gas pipes lead to your kitchen stove miles of water pipes miles of petroleum and miles of natural gas transmission lines to ton miles carried the transportation systems of this continent stand as follows railroads ton miles pipe lines motor vehicles electric railroads ile 11 inland waterways and airplanes |