It was in the confidence resulting from this masterly achievement that in 1872 some astronomers (among them Professor Alex. Herschel, one of Sir J. Herschel's sons) announced the probable occurrence of a display of meteors when the earth crossed the track of Biela's missing comet. An occurrence of this sort was alone wanting to complete the evidence for the meteoric theory. It had been found that the August Perseids move as if they followed in the track of a known comet; the path of the November Leonides had been shown to be identical with that of another comet; if astronomers could predict the appearance of meteors at the time when the earth should pass through the track of a known comet, even those who could not appreciate the force of the mathematical evidence for the new theory would be convinced by the meteoric display. Possibly such observers would have been satisfied with a meteor shower which would not have contented astronomers. The display must have special characteristics to satisfy scientific observers. The path of a body following Biela's comet being known, and its exact rate of motion, the direction in which it must enter our earth's atmosphere (if at all) is determined. Calculation showed this direction to be such that every meteor would appear to travel directly from the constellation Andromeda,--from a point near the feet of the Chained Lady. A meteor might appear in any part of the sky, but its course must be directed from that point, otherwise it could not possibly be travelling in the track of Biela's comet. The event corresponded exactly with the anticipations of astronomers. On the evening of November 27, 1872, many thousands of small meteors were seen. In England between 40,000 and 50,000 were counted. In Italy the meteors were so numerous that at one time there seemed to be a cloud of light around the region near the feet of Andromeda whence all the meteor-tracks seemed to radiate. The meteors were unmistakably travelling on the track of Biela's comet. They overtook the earth on a path slanting downwards somewhat from the north--precisely in the direction in which Biela's comet would itself have descended upon the earth if at any time the earth had chanced to reach the part of her path crossed by the comet's when the comet was passing that way.