SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 39 
miles, all the other sides in each of the six triangles can be eal- 
culated. 
We thus find ps the shooting star’s height when first seen, 
Ws its distance from W and Ls its distance from L; also p’s’ 
its height at the moment of extinction, and Ws’ and Ls’ its 
distances at that moment from W and L. 
The line s’k is drawn parallel to line p’p, omitted in the figure. 
Triangle p’pL gives the length of p’p and therefore of its equal 
s’k. Right triangle s’ks gives length of ss’. This length was 
(Wake Forest) 
traversed in six seconds. One-sixth of it is the shooting star’s 
velocity per second. Such observations and ecaleulations show 
that usually a shooting star’s height, when first visible is about 
75 miles; and when it disappears, about 50 miles. Also, that 
its velocity ranges from 8 to 44 miles per second—indieating 
that its velocity through outer space, just before it entered our 
atmosphere, was about 26 miles per second. — Its distance from 
the observer varies greatly, from 60 to 600 miles—possibly 770 
miles. 
The observed velocity is, of course, only relative to the earth. 
Its wide range, from 8 to 44 miles per second, is readily under- 
stood by considering Fig. 3. 
In this figure, the earth is represented turning eastward about 
