500 AGRICULTURAL ENGINEERING 



flushed as the second but generally uses more water. The 

 water is discharged from the second with considerable force, 

 and for that reason is preferred by some. 



Back Vents. In nearly all cities all fixtures are required 

 by law to have vents from the traps to prevent the water 

 which closes the pipe and prevents the entrance of foul gases 

 into the room from being siphoned over into the sewer. This 

 system of piping is shown in the accompanying figure; it intro- 

 duces considerable extra expense. In country houses there 

 is doubtless little danger in omitting this extra piping. 



There will be little difficulty in installing plumbing in a 

 house not built especially for the purpose, providing there is 

 room for it. There is some inconvenience in putting the 

 pipes in place, but in most cases they can be left in exposed 

 locations, which is some advantage. 



The plumbing referred to and of the quality suggested 

 will cost less than $200 almost anywhere in the Middle West ; 

 in fact, the average cost should not exceed $150. 



QUESTIONS 



1. What are some of the general considerations involved in the 

 installation of plumbing? 



2. How may plumbing be arranged in houses without furnace heat? 



3. How secure convenience in cleaning and inspection? 



4. What are the usual fixtures required? 



5. Discuss the merits of various grades of sinks. 



6. What should be avoided in the selection of a lavatory? 



7. Discuss the different types of water closets. 



8. What is meant by back venting? 



9. How much should the plumbing in an average farmhouse cost? 



