The plants of the foreign companies are probably the greatest installation in any single oil field in the world. The investment in pipe lines, pumping stations, storage tanks, refineries, terminals and ships represents close on $750,000,000; the length of the 161 pipe lines (practically all of them eight or ten inches in diameter) totals nearly 1,000 miles, while nearly 1,500 steel tanks, with a capacity of 60,000,000 barrels, furnish enough storage to fill a thousand ships. Through the pipe lines can pass, under high pressure, 750,000 barrels a day, although the average production for 1920 was about half of this amount. In the Mexican fields in April, 1920, the latest date for which figures are available, there were 304 wells in production, 148 located and 123 drilling. The total of commercially unproductive wells to that date was 464, including only 35 which showed oil in too small quantities. Three-fifths of all the wells drilled in Mexico have been dry holes, and to-day of 1,113 wells drilled and projected, only 75 which have actually flowed oil have run out of production. These last, however, include some of the greatest in the history of the petroleum industry. The vast investment and plant in the Tampico-Tuxpam fields produced in 1920 over 140,000,000 barrels of oil, one-fourth of all that was produced in the entire world, equaling some 40 per cent of the production of all the fields in the United States. The 1920 production was nearly five times that of 1913, when less than 26,000,000 barrels were extracted from the Mexican wells, and when Mexico’s total oil output was only one-ninth that of the United States and contributed less than one-twelfth to the production of the world. The growth has been steady and by tremendous strides, for when the pressure of war was on, the men who were taking out Mexican oil built up a production which between 1916 and 1917 brought an increase of 40 per cent and began a development that despite superhuman difficulties gained such momentum that between 1919 and 1920 the increase was 60 per cent.