An Aurora Observed in Missouri 111 
nomena. Here we may have an experimental approach to the true 
nature of auroras. At least it seems to bear out the theory of 
Stormer,* which states that electrically charged particles shot off 
at great velocities by eruptions on the sun reach the earth’s mag- 
netic field, which deflects them toward the magnetic poles. When 
they come into the upper portion of the atmosphere near the poles, 
they set up visible electrical discharges that we see as an aurora. 
A number of instances of observed solar activity followed by 
b 
on January 24th, and on the 25th he observed a second and very 
remarkable eruption near the same spot. Magnetic disturbances 
of great magnitude were observed at Greenwich and elsewhere simul- 
taneously with this aurora, and on the 27th as well. 
Upon observing the solar disc in the afternoon of May 22, 1932, 
the writer found one large spot in the southern hemisphere near 
e equator, and not far from the east limb. Three smaller spots 
were found in the same latitude, near the west limb, and they dis- 
appeared around the limb within the next few days. On May 24th, 
two days later, the large spot had been carried nearer to the cen- 
tral meridian by the rotation of the sun. ree small spots not 
present on the 22nd were visible south of the large spot, but very 
near it. By 6:00 p. m., May 27th, the large spot had passed the 
central meridian and the three small spots had completely disap- 
eared. e appearance of these spots on the 24th and their disap- 
pearance before the 27th, is evidence that there was considerable 
activity in their vicinity. The large spot was still visible on May 
30th. 
Dr. G. E. Hale, of the Mount Wilson Observatory, has informed 
the writer, in a letter, that he received word from Dr. Nicholson, 
in charge of solar work at Mount Wilson, that only one magnetic 
storm occurred during May; this was on May 29th and 30th. On 
Unfortunately, the writer had not observed the sun during June 
and therefore cannot present any evidence of solar activity preced- 
* Described briefly by Kennelly, 1932. 
