"One may picture, too, the sudden shifting of the attention, the swiftly spreading coils and bellyings of that blackness advancing headlong, towering heavenward, turning the twilight to a palpable darkness, a strange and horrible antagonist of vapour striding upon its victims, men and horses near it seen dimly, running, shrieking, falling headlong, shouts of dismay, the guns suddenly abandoned, men choking and writhing on the ground, and the swift broadening-out of the opaque cone of smoke. And then night and extinction " nothing but a silent mass of impenetrable vapour hiding its dead."