Let us see what that means. It means laboratory tests to start with. Here are brought many samples of the body paper, wad paper, metals, waterproofing mixture, fulminate of mercury, sulphur, chlorate of potash, antimony sulphide, powder, wax, and other ingredients, and even the operating materials such as coal, grease, oil, and soaps. In the laboratory we see expert chemists and metallurgists with their test-tubes, scales, Bunsen burners, retorts, tensile machines, microscopes, and other scientific looking apparatus, busily hunting for defects. For example, one marker is examining a supply of cupro-nickel, such as is used in jacketing certain bullets. A corner of each strip is first bent over at right angles, then back in the other direction until it is doubled, then straightened. It does not show the slightest sign of breaking or cracking, in spite of the severe treatment, therefore it is perfect. Let but the least flaw appear, and the shipment is rejected. [Illustration: WHAT A SHOT TOWER LOOKS LIKE SHOT TOWER--TALLEST BUILDING IN CONNECTICUT] [Illustration: LARGEST CARTRIDGE EQUALS MORE THAN 1,000,000 OF SMALLEST (HELD ON HAND)] Two large iron cylinders descend in the center, coming down through the ceiling from above; we are invited to look through an open port in one of these. We see nothing but the whitened opposite wall, against which a light burns. It appears absolutely empty, though within it is raining such a swift shower of invisible metal that if we were to stretch our hands into the apparently vacant space they would be torn from our arms. A large water tank below is churned into foam with the impact of the falling shot, and as we look downward we make out finally the haze of motion. It is so interesting that we take the elevator and rise ten stories to the source of the shower. Here high in the air are the large caldrons where many pigs of lead, with the proper alloy, are melted into a sort of metallic soup. This is fed into small compartments containing sieves or screens, through the meshes of which the shining drops appear and then plunge swiftly downward. But this only begins the process. Taken from the water tanks and hoisted up again, the shot pellets, in a second journey down, through complicated devices, are sorted, tumbled, polished, graded, coated with graphite, and finally stored. The pictures shown in this story were prepared especially to illustrate this story of “How Man Learned to Shoot” by the Searchlight Library for the Remington Arms Company. [Illustration: FORGING A MONSTER GUN Photo by Bethlehem Steel Co. This photograph shows gun ingots after being “stripped” and “cored.”] [Illustration: Photo by Bethlehem Steel Co. This photograph shows a gun ingot in the process of being forged under forging press.] [Illustration: Photo by Bethlehem Steel Co. This photograph shows a gun being fired at the Proving Grounds for test.] The Parts of a Big Gun