Oil wells at Potrero, Mexico, 15 March 1911.
© Science Museum / Science & Society Picture Library
Three photographs taken at the oilfields of Potrero, Mexico, two showing drilling equipment and the third a 'gusher', an oil well from which the oil flows out under pressure without needing to be pumped. The amount of oil ejected can be prodigious; the Lakeview No 1 gusher in California flowed continuously for 18 months beginning, producing an estimated 8.2 million barrels of crude oil. The caption beneath this photograph of the gusher at Potrero states that the oil was still flowing as strongly as it had been 3 months previously. Mexico has very extensive oil reserves. Initially these resources were exploited by British and American oil companies, but in 1938 the Government of Lazaro Cardenas nationalised the Mexican oil industry.