166 AGRICULTURAL ENGINEERING 



on which the brick is laid. In order to allow for the expan- 

 sion and contraction due to changes of temperature, an 

 expansion joint must be left occasionally. 



Concrete Roads. Owing to a reduction in the cost of 

 Portland cement, concrete is now used to a limited extent 

 in the construction of roads. One objection to concrete 

 roads is that they are slippery, but this may be overcome. 

 The construction of concrete roads has not as yet become 

 standardized. 



QUESTIONS 



1. What is a stone road? 



2. Describe the Telford form of construction for stone roads. 



3. Describe the construction of the macadam road. 



4. What are the requisites of stone for road construction? 



5. Why should road stone be tested? 



6. Describe the construction of water-bound stone roads. 



7. How much should a stone road be rolled at the finish? 



8. Describe two methods of constructing bituminous macadam 



roads. 



9. How much do macadam roads cost per mile? 



10. How should macadam roads be maintained? 



11. Where may brick roads be constructed advantageously? 



12. Describe the construction of brick roads. 



13. What is one objection to the concrete road? 



