188 | ANNUAL REPORT SMITHSONIAN INSTITUTION, 1944 
the first time it has made it possible for us to see and identify mole- 
cules, and to photograph the influenza virus. It has revealed, in in- 
finite detail, the true structures of fibers, crystals, and pigments. The 
submicroscopic world is now opened wide for exploration. Bacteria, 
tissues, and minute particles of matter have been brought within 
range of man’s eye, for the electron microscope, many times more 
powerful than the strongest optical microscope, permits magnifica- 
tions up to 100,000 diameters. A needle on such a scale of magnifica- 
tion would appear as huge as the Washington Monument; a blood cor- 
puscle as large as the wheel of an automobile and a football field 
five times the size of the United States. 
Wartime industrial research and engineering have rushed into use 
still another branch of radio—the art of utilizing high-frequency 
radio waves for heating. It violates no military secret to report that 
in this new field of radiothermics, a laminated airplane propeller can 
be processed in minutes compared with hours required by ordinary 
heat and pressure methods. In many cases where uniform heat under 
accurate control is necessary in industrial processes, radiothermics 
offers great promise in efficiency and time saving. The wide scope 
of its application ranges from case-hardening steel to dehydrating 
foods, from gluing prefabricated houses to seaming thermoplastic 
materials by means of a “radio sewing machine.” ‘These accomplish- 
ments are all based upon the simple fact that microwaves, in penetrat- 
ing an object, encounter resistance and create heat. 
Farther afield from communications, research men are exploring 
supersonic vibrations, far above the range of the human ear. The use 
of these ultrasonics in chemistry may open a field in which high- 
intensity sound accelerates chemical reactions. Experiments also 
indicate important possibilities in many other fields including under- 
water communication, emulsification of liquids, and precipitation of 
dust from the air. 
We attribute all these lines of progress to the science of electronics. 
The heart of that science is the radio tube. Millions and millions of 
radio-electron tubes are on duty around the world. They are being 
manufactured in the United States at the rate of 400,000 a day. The 
communities in which they are made are on the front line of pro- 
duction. The great importance of each radio tube that moves off the 
production lines can only be envisaged by considering the many func- 
tions it performs in helping to win the war. The delicate finger of 
the worker who makes the tubes has a task as vital as the finger of a 
soldier on the trigger of a rifle. 
Likewise, radio-electron tubes are as important in peace as in war. 
They are the master keys to revolutionary advances in radio. They 
have registered the sound of footprints in the past; they are the 
