go SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 
its axis—N its north pole—and moving in its orbit eastward, 
the Sun being in the direction of S. 
On observer at O has just passed into the evening shade. 
Relative to him, the earth’s orbital motion, 18 miles per second, 
is downward. If he sees a nearly overhead shooting star it is 
overtaking the earth, and its velocity, relative to the earth, is 
26 — 18 =- 8 miles per second. An observer at O’ is soon to 
ereet sun-rise. Relative to him, the earth is moving upward 
18 miles per second. A shooting star above him is meeting the 
Figs 
earth, and its relative velocity is 26 + 18 — 44 miles per second. 
To either observer, a shooting star crossing the earth’s path 
will show more nearly the average velocity. 
A notable shower of shooting stars occurred on the 24th, of 
November 1892. It continued for three hours after 8 0’clock 
in the evening. 
That periodical star shower—the Bielids—will oceur again 
this November—in the evening of some country. It may oceur 
during our evening hours. If so, notice the slow motion of the 
““falling’’ stars. Should the reader be privileged to see the 
next Leonid star-shower, expected in the early morning hours 
of November 15, 1933, he will note the startling rapidity of the 
star-fall. 
In general, the velocity of the evening shooting stars is less 
