520 



MACHINES, WORK, AND ENERGY 



The 19th century was a period when there were few machines 

 and labor-saving devices in the home. All this means that 

 knowledge concerning machines and machinery largely dis- 

 appeared from the home. 



614. Knowledge of Machinery again Becoming Necessary 

 in the Home. While almost all the primitive industries have 

 disappeared from the home, there have recently come into the 

 home many new forms of machines and devices all of which 

 make necessary some knowledge of applied science. Lighting 

 systems of various kinds, heating devices, systems of water 

 supply, plumbing, vacuum cleaners, sewing machines, and 



FIG. 322. A farm power house. 



motors for the operating of machinery of various kinds all 

 these conveniences require knowledge of applied science. The 

 housewife with no knowledge of the laws of science can not 

 expect to handle successfully the conveniences of the modern 

 home. 



615. Knowledge of Mechanics Necessary for the Farmer. 

 Today the farmer requires a knowledge of mechanics at every 

 turn. Most of the work on the farm is now done by means of 

 machinery. The farmer with no knowledge of the laws of 

 mechanics can not operate intelligently his plows, cultivators, 

 mowing machines, binders, seeders, or numerous other tools 



