718 



SANITARY SCIENCE. 



that is essential, and illustrating the vital prin- 

 ciples of efficient house-drainage." 



Modern plumbing practice is not mere the- 

 ory, nor the result of the whim or interested 

 invention of the plumbing craft ; it is the prod- 

 uct of the experience of hundreds of keen and 

 watchful observers, many of them with scien- 

 tific training, including not only plumbers and 

 builders, but architects, engineers, and physi- 

 cians. It has been established that drains and 



quickly corrode and admit sawer-gas ; and in 

 utilizing soil-pipes filled with sand-holes, which 

 may crack and leak. Poor workmanship may 

 be due to ignorance in the workman or to the 

 parsimony of the customer. It may be poor 

 because of the inferior materials used, or from 

 the neglect of the plumber to put -them to- 

 gether securely. Defects in design are most 

 frequently due to the unwillingness of the 

 house-owner to pay for a thorough work, but 





sewers become foul and create gases dangerous 

 to health; that these gases will gain an en- 

 trance through leaks or flaws in case of bad 

 workmanship; that traps can be emptied by 

 siphonage, unless security is provided in the 

 shape of ample ventilation; and that this ven- 

 tilation must be thorough and complete. 



Defetts. The three prime causes of bad 

 plumbing have been shown to be poor ma- 

 terials, poor workmanship, and poor design. 

 Examples of the first deficiency are seen in the 

 use of wood, brick, or stone, instead of iron or 

 tile, as material for underground drains ; in 

 employing light-weight pipes and traps, which 



they are also caused by the plumber's own 

 ignorance and botching. In some cases they 

 may be traced to amateur experimenting in 

 sanitation. The following are some of the 

 most common sanitary defects in ordinary 

 dwellings, which have been chief agencies in 

 spreading and developing diphtheria, typhoid 

 fever, and other zymotic diseases : 



Broken drains under cellar-floors, leaking 

 foul gases to be borne up into the living-rooms 

 of the houses, and cellar-drains connecting di- 

 rectly with the sewer or cess-pool, without 

 traps or with traps whose water-seal has evap- 

 orated. 



