SOLAR RADIO ASTRONOMY—MAXWELL 307 
May 10 and 11. These great increases in cosmic rays, above the ter- 
restrial atmosphere, may, or may not, constitute an additional] hazard 
for space travel. It is, however, of considerable interest to note that 
their emission from the sun is detected by solar radio astronomers 
approximately 1 hour in advance of their arrival at the earth. 
CONCLUSION 
Over the past decade the information obtained by radio techniques 
has revolutionized existing theories of the processes that occur in the 
solar atmosphere. It has also helped elucidate the complicated series 
of events that originate in the sun and subsequently affect the earth’s 
atmosphere. Early theories advanced to account for thermal radio 
emissions from the solar atmosphere have now been well substantiated, 
and some understanding has also been achieved of the nonthermal 
processes which give rise to intense radio outbursts. Within the 
next few years we may expect to see a large accumulation of results 
from the radio helioscopes which are now being put into operation 
throughout the world, increased efforts to improve the present resolv- 
ing power of radio instruments, and the extension of sweep frequency 
observations even further over the radio band. 
