The letter S was photographed. Samples of it were taken. The air currents in and around it were measured by instruments operated through ports in airplanes readied just for the task. Various tagged atoms were then dusted into the letter and their courses were pursued by scientists in helicopters, armed with counters. From the ground, spectroscopes were trained upon the initial and diffraction gratings laid bare its spectrum. Everything was done that had been planned at the University of Chicago--and elsewhere in the city--and by a variety of physical scientists who phoned and wrote in their suggestions. Meantime, an H formed next to the S and subdued titter filled the watching streets. The third plane followed when an ineluctable I was added to the throbbing sky-scene. As if this was carrying cosmic anagrams too far, military aircraft undertook to break up the phenomenon--also according to plan. Four-letter words, so called, are one of the great American taboos. In this connotation, nuts and crap are not considered precisely forbidden, though each has a special reference which is impermissible. All people know all the four-letter words, of course, since they are scribbled everywhere and commonly used by lower caste persons when under duress. And substitute words are employed, by the most devout, for every profane or obscene term. So the taboo is of a magical nature (speaking anthropologically). Primitive people, such as the Americans, generally employ medicine men, witch doctors, or priests against magical threats. In this case, however, physical rather than spiritual results were expected from the efforts of the airmen. First, formations of jets flew through the cloud-spelling--along its own paths and then in series of crisscrosses. Nothing much happened; the streaming jets blew wisps and curls of mist out of alignment but it swiftly filled itself in again. Heavy bombers followed, but the washes of their props were equally ineffectual. During the bomber maneuvers, furthermore, one Paul Kully, a student flier, eluded the police and ventured close to the now-completed T. The pilot of the leading bomber, a B-36, took evasive action too late, and Mr. Kully's light plane, shorn of a wing and set on fire, came spiraling to earth--a sight enormously exciting to the already enthralled Chicagoans.