National Geographic : 1954 Jul
76 Harold E. Edgerton Sea's Pressure at 2,500 Feet Crushes a Steel Flash Lamp Below: Dr. Harold E. Edgerton, checking damage, de cided to house his lamp in a tougher Pyrex glass tube. Above: A flash unit, a stop-motion camera, and a sil houette camera (bottom) developed by Dr. Edgerton with National Geographic Society aid, descend into the sea. The silhouette camera, used for portraying minute organisms, makes a shadowgraph of a disk of water 1 inch thick, 4 inches in diameter. Triggered to shoot when horizontal, it takes pictures every 15 seconds. white fishes and then realize they are big shrimps kicking their elongated legs. They are about five inches long. Now come smaller shrimps with their long antennae bent at right angles, and a strange, solitary fish, a triangu lar silvery phantom about 20 inches long. Suddenly an agitated wake of water ripples across my field of vision. "That was a big one!" I yell. "Maybe a cephalopod." It goes too fast to be identified. Back comes the wake again, and from the passing blur materializes a beautiful squid, which stops for a fraction of a second as if dazzled by the searchlight beam. Before it vanishes again, I clearly see its rocketlike head and its 10 arms. It is about 1/2 feet long, and it leaves a blob of ink. The ink is white. Now, it is well known that octopuses and squids of shallow waters discharge dark-brown ink. I switch off the searchlight. The squid ink glows phosphorescently in the dark. As I stare at this apparition, another squid jets luminous ink in front of the porthole. My excited description of these events does not impress the pilot. "Let me have a look," says Houot, skeptically. The next squid makes a believer out of him. It lays a white cloud that practically blots out the window. He sur renders the observation post to me again. We are approaching the bottom. I peer down intently to where our shaft of light fades into the obscurity of the unknown. "Four thousand feet," says Houot. My heart beats rapidly then, for I discern, down below, a faint milky glow-our droplight reflecting from the floor of the sea. For the first time, our bathyscaphe is about to land.