146 FIRESIDE SCIENCE. 



time we think but little of this pipe is used in any 

 section of the country for water conduit. 



BRASS PIPE. 



Compound metals used for water-pipes must be 

 looked upon with disfavor by chemists. And yet 

 some alloys resist oxidation or other chemical 

 change in a most remarkable manner. We kijow 

 of no subject which more imperatively demands 

 patient and careful investigation than that of al- 

 loys. It is a curious fact that aluminum and mag- 

 nesium, when combined with each other and with 

 other metals in certain proportions, will oxidize 

 so rapidly as to fall into a powder almost instantly; 

 while in other proportions the compound resists 

 the action of oxygen to a degree approaching 

 that of the noble metals. A mixture of copper 

 and zinc may possibly be devised, which, when 

 formed into pipe, will convey water safely ; but of 

 such we have no knowledge. A brass water-pipe 

 is now being manufactured and introduced, we 

 learn ; but such should not be hastily adopted by 

 any one. 



CLAY PIPES. 



The common glazed clay or " stone-ware " pipe 

 has been used to a considerable extent for conduct- 

 ing water, and where the pressure is slight it may 

 serve a good purpose. There is a difficulty, how- 



