somewhat yellowed disk beginning to be eaten into from below by dark obscuring matter. Meanwhile the whole surface of the plain was covered with matter being thrown up into the air as the motion continued outward from Zero. In a matter of a few seconds more the disk had nearly stopped growing horizontally and was beginning to extend in a vertical direction while its appearance had transformed into that of a bright glowing distinctly red column of flame mixed with swirling obscuring matter. The column looked rather like smoke and flame rising from an oil fire. This turbulent red column rose straight up several thousand feet in a few seconds growing a mushroom-like head of the same kind. This mushroom was fully developed and the whole glowing structure complete at about 15,000 feet altitude. I do not recall whether this stage was reached before or after the arrival of the shock. At T +30 I realized the shock was due very soon and I huddled closer to the ground in
