The early morning sun warmed the white marble of the Jefferson Memorial and glinted from the soldiers' helmets and the roofs of the packed cars that crowded forward in a slow-moving stream. All the gentlemen of Congress were there, the passage of their cars cleared by the screaming sirens of motorcycle policemen. Around and under the wheels of the official cars pressed a solid wave of government workers and common citizens of the capital city. The trucks of the radio and television services pressed close, microphones and cameras extended. The stage was set for a great day. Neat rows of olive drab vehicles curved along the water's edge. Jeeps and half-tracks shouldered close by weapons carriers and six-bys, all of them shrinking to insignificance beside the looming Patton tanks. A speakers' platform was set up in the center of the line, near the audience. At precisely 10 a.m., General Wingrove stepped forward and scowled at the crowd until they settled into an uncomfortable silence. His speech was short and consisted of nothing more than amplifications of his opening statement that actions speak louder than words. He pointed to the first truck in line, a 2½-ton filled with an infantry squad sitting stiffly at attention. The driver caught the signal and kicked the engine into life; with a grind of gears it moved forward toward the river's edge. There was an indrawn gasp from the crowd as the front wheels ground over the marble parapet--then the truck was plunging down toward the muddy waters of the Potomac. The wheels touched the water and the surface seemed to sink while taking on a strange glassy character. The truck roared into high gear and rode forward on the surface of the water surrounded by a saucer-shaped depression. It parked two hundred yards off shore and the soldiers, goaded by the sergeant's bark, leapt out and lined up with a showy _present arms_. The general returned the salute and waved to the remaining vehicles. They moved forward in a series of maneuvers that indicated a great number of rehearsal hours on some hidden pond. The tanks rumbled slowly over the water while the jeeps cut back and forth through their lines in intricate patterns. The trucks backed and turned like puffing ballerinas. The audience was rooted in a hushed silence, their eyeballs bulging. They continued to watch the amazing display as General Wingrove spoke again: "You see before you a typical example of Army ingenuity, developed in Army laboratories. These motor units are supported on the surface of the water by an intensifying of the surface tension in their immediate area. Their weight is evenly distributed over the surface, causing the shallow depressions you see around them.