This ended the main spectacle. Most of the planes descended to earth. The word--awful, unprintable, unacknowledgable, obscene and illegal--which, as has been noted, many use in private and in public, and everybody sees constantly chalked on fences and carved into cement by rude boys--and which is pronounced "shucks" by the super-superstitious--now rode in the Chicago heavens. The breeze dropped. Surrounding cumulus clouds retreated as if to frame the sign; air movement died aloft; the four corrupt letters and their following exclamation point came to rest directly over the Loop. This was widely regarded as the supreme practical joke--until the extras began to appear. These were in a way disappointing: photographers had spiraled vainly in the high blue, for not one newspaper made bold to print a picture of what all could see if they bent their necks. But the published statement concerning the scientific investigation had a tendency to diminish the widespread mirth. Dr. A.B. Cummings, acting for a General Committee, wrote the report. It said, in part: "... a gross examination showed a special arrangement of clouds which cannot be accounted for by the laws of chance. Emphasis should be made of the fact that absolutely no clue to human agency, domestic, enemy, or other--either in the air or on the ground--was found. There was no evidence of interference from the stratosphere above. No abnormal radiation was detected. No use of sonic devices may be presumed in view of the study. After the mass became stationary, it was found that currents of air were moving as they should (according to all known laws and principles of meteorology) above, below, and on both sides of the phenomenon. " ... that last fact, taken by itself, is perhaps the most disturbing, although it is possibly equaled by one other. Viz--the mass is not subject to the known laws of dissipation. The slipstream of jets and the wash of huge propellers ought to have caused it to disintegrate in a few minutes. They made only a moderate and local effect which, again in violation of understandable principles, was offset by the reassemblage of the mass along its original contours. It has been proposed that if there is a repetition of this totally unprecedented and inexplicable effect, antiaircraft artillery with ordinary fused shells be used in an attempt to break it up. In such a case, citizens will have to be sheltered from falling fragments during the bombardment. This will probably be tried--although the tendency of the mass to hold its shape, resembling as it does a similar tendency in plastics of special molecular structures, at least suggests that even artillery may not be effective....