e of an arduous
character, but the results amply repaid the labour. It was shown that
with the smaller ellipses it would be impossible to obtain a
displacement even one-half of that which was observed. These four orbits
must, therefore, be rejected. Thus the demonstration was complete that
it is in the large path that the meteors revolve.

The movements in each revolution are guided by Kepler's laws. When at
the part of its path most distant from the sun the velocity of a meteor
is at its lowest, being then but little more than a mile a second; as it
draws in, the speed gradually increases, until, when the meteor crosses
the earth's track, its velocity is no less than twenty-six miles a
second. The earth is moving very nearly in the opposite direction at
the rate of eighteen miles a second, so that, if the meteor happen to
strike the earth's atmosphere, it does so with the enormous velocity of
nearly forty-four miles a second. If a collision is escaped, then the
meteor resumes its onward journey with gradually declining velocity, and
by the time it has completed its circuit a period of thirty-three years
and a quarter will have elapsed.

The innumerable meteors which form the Leonids are arranged in an
enormous stream, of a breadth very small in comparison with its length.
If we represent the orbit by an ellipse whose length is seven feet, then
the meteor stream will be represented by a thread of the finest
sewing-silk, about a foot and a half or two feet long, creeping along
the orbit.[34] The size of this stream may be estimated from the
consideration that even its width cannot be less than 100,000 miles. Its
length may be estimated from the circumstance that, although its
velocity is about twenty-six miles a second, yet the stream takes about
two years to pass the point where its orbit crosses the earth's track.
On the memorable night between the 13th and 14th of November, 1866, the
earth plunged into this stream near its head, and did not emerge on the
other side until five hours later. During that time it happened that the
hemisphere of the earth which was in front contained the continents of
Europe, Asia, and Africa, and consequently it was in the Old World that
the great shower was seen. On that day twelvemonth, when the earth had
regained the same spot, the shoal had not entirely passed, and the earth
made another plunge. This time the American continent was in the van,
and consequently it was there that the sh