312 AGRICULTURAL ENGINEERING 



The construction of the implement house will be discussed 

 in a later chapter. 



Painting. Painting is simply providing each implement 

 with a house of its own. Wooden parts deteriorate rapidly 

 when moisture is allowed to penetrate the surface. Wood 

 decays and warps, rendering it weak and useless for the pur- 

 pose for which it is used. Unprotected iron or steel when 

 exposed to the weather unites with oxygen of the air, or 

 rusts, gradually giving up its strength. Steel bridges decay 

 in this manner so rapidly that they must be replaced after 

 a term of years. To protect these metals, their surfaces are 

 coated with paint to keep out the moisture and air. Rail- 

 road companies and large corporations find it profitable to 

 keep their steel bridges and stuctural work well painted. 



Perhaps there is no better paint for implements, not tak- 

 ing into account a personal dislike which some have for the 

 color, than red lead and linseed oil. This paint will adhere 

 well to clean surfaces of wood and iron, and is affected about 

 as little by the weather as anything that can be used. 



Besides prolonging the life of the machines themselves, 

 a machine dressed in a good coat of paint commands more 

 respect and is looked upon as being a better machine. The 

 author can recall specific instances where a coat of paint 

 has increased the selling price of machinery fifty per cent 

 or more. 



QUESTIONS 



1. How much does the American farmer spend annually for farm 

 machinery? 



2. What percentage is this of his gross and of his net income? 



3. What is the average depreciation of farm machinery? 



4. Explain why the repair of farm machinery is so important. 



5. Describe a system of keeping all farm machinery in good repair. 



6. Why is the housing of farm machinery so important? 



7. Give several reasons why machinery should be kept painted. 



