202 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1941 



The development of the loud-speaker practically ruined this active 

 business. The early sets used vaccuum tubes supplied by direct cur- 

 rent, requiring plate and filament batteries. This created a heavy 

 production of dry batteries that was subsequently curtailed by the 

 development of plate-battery eliminators. Later, the development 

 of the copper-oxide rectifier eliminated the use of the storage bat- 

 tery for filaments, and still later, the development of a.-c. tubes so 

 completely changed the design of radio receivers that it rendered 

 many inventories and factory equipments obsolete. 



The most recent step in this evolution — and one that shows the 

 cyclic character of many industrial developments — is the battery- 

 operated portable set that has suddenly become so popular. It is 

 additionally significant that although a tube development displaced 

 the early battery set, another development of tubes brings the bat- 

 tery back — ^the perfection of a tube that operates successfully on li/^ 

 volts. 



This last development also shows the rewards from the policy of 

 letting the obsolescence caused by science take its seemingly ruthless 

 course. The new battery-operated radios do not offer new competi- 

 tion for established types of radio sets, but instead simply create or 

 uncover an additional demand for radios. The demand for batteries 

 and for tubes promises to reach an all-time peak. 



Similar successive steps of development occurred in illumination. 

 A large kerosene-lamp industry was rendered obsolete, particularly 

 in metropolitan districts, by the coming of the gas mantle. It, in 

 turn, was replaced by the electric lamps. Now a new family of 

 lamps — the gas-discharge lamps, which include sodium-vapor, high- 

 pressure mercury-vapor, and fluorescent units — with eflSciencies sev- 

 eral times those of incandescent lamps, have demonstrated their 

 practicability. It is still too soon to predict to what extent they will 

 become the universal illuminants, but there is more than a hint that 

 illuminant evolution is not at an end. No one in the industry thinks 

 for a minute that the more efficient light sources presage a decrease 

 in the requirements for energy or equipment. On the contrary, as 

 in the past, this improvement should promote further expansion. 



INDUSTRY FINDS MANY BENEFITS FROM ORGANIZED RESEARCH 



The industrial laboratory has served the march of electrical prog- 

 ress in many ways. Not the least of these is that it has served to 

 bring the scientist, the design engineer, and the application engineer 

 into closer contact. They now talk the same language and use the 

 same tools. Universities are giving more attention to the training 

 of industrial scientists, and within the last few years, important 

 meetings have been devoted to discussions of the application of 

 physics to industry. 



