In 1896 Antoine Henri Becquerel of France left some uranium salts lying in the dark near a photographic plate. When he developed the plate he found that some sort of rays from the uranium, passing through a metal container and several other obstacles, had left an image on the plate. Thus by accident Becquerel, who shared a Nobel Prize with Pierre and Marie Curie, discovered radioactivity.
The same principle underlies a technique, explained last week, for ferreting out defects in thick masses of steel. At the convention of the American Society for Testing Materials in Manhattan, Physicist E. V. Lange of Radium Chemical Co. demonstrated with a capsule containing one-tenth of a gram of radium. Gamma rays shooting out at a million or more volts passed through steel castings a foot thick, photographed the interior structure on X-ray films 10 by 12 in. in size. Tested by this method are steering posts of ships, turbines, valves, high-pressure steam pipes. Dr. Lange reported that in most Army and Navy purchases of heavy steel equipment, radium-testing is now required.
Another testing device described at the meeting was a vibrator which causes a battleship "to shiver like a man with the ague." The machine has two heavy weights rotating eccentrically so that vibrations are set up in all riveted joints or welded seams and unhealthy tremors exposed. Declared C. H. Gibbons, technical adviser to Baldwin-Southwork Corp.: "When this machine is attached to a battleship still under construction, it is possible to simulate the stresses and strains to which the ship would be submitted during a storm at sea."
Dr. Arno Carl Fieldner of the U. S. Bureau of Mines raised the old bugaboo about the imminent exhaustion of oil & gas. There was enough coal, he said, to last 2,100 years. But the known reserves of natural gas were 30 to 40 trillion cu. ft., of oil 13 billion barrels. At the present rate of consumption the petroleum would be gone in 13 years—but Dr. Fieldner predicted that discoveries of new pools and more efficient production techniques would stretch out the supply for a century. Unless "greater social control" was forthcoming, known supplies of gas would vanish in 20 years.
One impressively successful technique for hiking oil production is treatment with acid. In certain limestone formations, acid treatment not only "brings in" or increases production on new wells but rejuvenates old ones. Object of pumping in acid is to eat out new channels in the limestone. Hydrochloric acid is used, chemically inhibited so that it will not attack steel casing or tubing. The acid doctor pulls out the tubing and pumping equipment, runs the tubing back with a packer 15 ft. above the bottom so acid will not run up the hole, squirts in 1,400 to 3,000 gal. of HCl. Rushing through a two-inch tubing, the acid eats into the | limestone so fast that it creates a partial vacuum at the top of the line.