174 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1945 



plastic parts for complications and housings. Plastics can handle 

 electricity but welcome metal for protection and for the boxes that 

 are fastened to the wall. Airplanes have hundreds of plastics parts, 

 where the light weight really does a job, but combined with metals 

 where metals are helpful from the strength standpoint. The list of 

 such combinations is endless. 



I recently saw an all-plastic alarm clock, a completely illogical try 

 if ever there was one. The combined cost of molds and molded parts 

 would have placed the selling price at four or five times that of any 

 much better metal clock. And yet there are good reasons for clock 

 cases finished in plastics. Color, the low cost of intricate shape, 

 warmth to the touch, etc., in combination with the basic metal design 

 make a salable article. 



In considering plastics as design materials, therefore, please re- 

 member two things: First, there are many plastics, just as there are 

 many metals ; if one plastic does not prove the answer to your problem, 

 look around a bit and see if there isn't another that is more logically 

 suited. Second, include plastics in your design thinking as a com- 

 plementary material to your metal experience ; investigate every pos- 

 sibility of combining a metal and a plastic to utilize the best features 

 of each. 



The very fact that plastics production is only 350,000 tons per year 

 compared to the relatively enormous production figures of metals (90 

 million tons of steel, 1 million tons of aluminum, etc), tied to the 

 widespread discussion of plastics in the public press and in engineer- 

 ing magazines like this must mean only one thing : no material with 

 that small a volume could get around enough on its own steam in the 

 last 5 years to make the impression that plastics have already made ; 

 the explanation is that the most important applications of plastics 

 have been in combination with their bigger brothers, the metals. 



