SECRETARY'S REPORT 11 



Smithsonian is one of the best in the world. The thoughtful visitor 

 who studies them learns not only a mechanical but also a sociological 

 lesson of importance. 



17. POWER MACHINERY 



In the Hall of Power Machinery the visitor sees how human beings 

 have progressed from the use of their own puny muscles to the great 

 power devices of our industrial age. Here original machines and 

 patent models illustrate the contribution of engineers and inventors 

 such as Stevens, Corliss, Otto, and Diesel. By diagrams and pictures, 

 waterwheels and windmills are shown. Included is a working model 

 of a classical heat engine that was used to open and close temple doors 

 in ancient Greece. Major displays demonstrate the invention and the 

 development of the steam engine portrayed by a series of working 

 models of great early steam engines which may be activated by each 

 visitor at the push of a button. Also on display are the beginnings 

 and indeed the full development of the internal combustion engine 

 and some of the early devices of Edison and others that show the rise 

 of the use of electricity as a power source. A permanent display of 

 the role of atomic energy in peacetime activity and defense is not yet 

 open to the public, but a number of temporary exhibits on this subject 

 have been presented from time to time by the Smithsonian. 



18. FARM MACHINERY 



In the Hall of Farm IMachinery are shown a selection of the imple- 

 ments and devices which man has contrived to further his basic work 

 of securing food from the soil. The emphasis is upon the history of 

 American agricultural implements. Here, for example, the visitor 

 may trace the evolution of the plow as used by North American settlers 

 from Europe from the earliest days to the present. One interesting 

 phase of this development shows how President Thomas Jefferson 

 used his mathematical and scientific knowledge to make one of the first 

 real improvements in the plow in several thousand years. Also shown 

 are some of the "historic firsts" of the more complex agriculture 

 machineiy which has made America famous throughout the world. 

 These exhibits show how the development and use of labor-saving 

 machinery for planting, cultivating, and harvesting crops helped solve 

 the problems of feeding America's rapidly growing urban population 

 after the Civil War. 



19. PRINTING ARTS 



Another specialized group of industrial devices is shown in the new 

 Printing Arts Hall. The gradual development of pictorial and text 

 printing is illustrated in these displays. The famous printing press 

 used by Benjamin Franklin in London in 1726 is here. The emphasis 



