242 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1951 



As I have already mentioned, the most recently developed television 

 pick-up tube, the vidicon, employs a target consisting of a photocon- 

 ductive material, that is, a material which conducts electric current 

 under the influence of light. Employed in a simple photosensitive 

 cell, such a material does not emit free electrens into space and hence 

 does not fit into the realm of "electronics" in the narrower sense. Yet, 

 materials from the larger family of the semiconductors, to which it 

 belongs, are playing an increasing role in electronic apparatus — not 

 only as components of tubes utilizing electron beams, such as the 

 vidicon, but also quite apart from vacuum devices: in the form of 

 the crystal rectifier and the transistor they fulfill certain requirements 

 previously met only by vacuum tubes. 



Wliereas, at present, there is little reason for expecting wholesale 

 replacement of vacuum tubes by their semiconductor equivalents — 

 certain basic shortcomings of the latter militate against this eventu- 

 ality — the crystal elements will not only find increasing use in spe- 

 cialized apparatus where compactness is of primary importance but 

 will also be incorporated more and more into the design of more con- 

 ventional electronic equipment. Here also the trend is toward com- 

 pactness, as exemplified by the increasing use of printed circuits. In 

 this connection the crystal diodes and triodes represent but one phase 

 of a constant search for improved components for electronic appa- 

 ratus. From another point of view, the intensive preoccupation with 

 the properties of the solid state, which has led to their discovery 

 and development, is creating a fund of knowledge that has already 

 borne rich fruit in the development of efiicient phosphors, ferromag- 

 netic materials, and crystal counters. This is bound to contribute ma- 

 terially not only to the electronic industry, but all other industries as 

 well, and to supply effective new tools for scientific investigation. 

 Wliatever the future of electronics may be in the ensuing half century, 

 it is certain to profit from fundamental research as it has in the past 

 and to repay its debt generously in the form of instruments and 

 methods to carry out the tasks of research. 



In the past half century electronics has demonstrated its ability to 

 annihilate distance for both sound and sight. In countless ways it 

 has aided human safety and relieved man of routine efforts. To the 

 scientist it has proved itself an indispensable aid in research. No 

 prophet is needed to state that, in the future, the application of elec- 

 tronics in these fields will be even wider, its usefulness even greater ; 

 more than that, as the past amply shows, no prophet can have sufficient 

 imagination to predict, at the present time, just what forms these 

 further applications, this increased usefulness may take. Yet one 

 thing is certain : in the future as in the recent past electronics will 



