540 THE POPULAR SCIENCE MONTHLY, 



the advantages are claimed for it of self -lubrication, greater wearing 

 capacity than any other metal or alloy, coolness under friction, great 

 tensile strength combined with hardness, and non-liability to fracture. 



Phosphor-tin is a compound designed to be added to copper for the 

 making of phosphor-bronze. 



The history of the practical manufacture of aluminum does not ex- 

 tend very far back into the past ; in fact, its commencement dates within 

 the limits of the present generation. The three International Exhibi- 

 tions which have been held in Paris since aluminum began to be worked 

 on a commercial scale form so many landmarks in its progress. In 1855 

 it was met with for the first time in the Palais d'Industrie, in the form 

 of a large bar, and was exhibited as silver produced from clay. In 

 the Exposition of 18G7 it was to be seen in a more advanced stage, 

 worked up into castings and various kinds of useful and ornamental 

 articles. There also for the first time was seen the alloy aluminum- 

 bronze. The Paris Exhibition of 1878 witnessed the maturity of the 

 aluminum manufacture and its establishment as a current industry, 

 having a regular demand and supply for certain purposes within the 

 limits permitted by its somewhat high price. A little more than two 

 years ago Mr. James Webster perfected his invention for producing 

 aluminum, which is now being practically worked, and gives, it is 

 claimed, alumina without a trace of iron, and free from contamina- 

 tion with other foreign substances. The process is being worked by 

 the Aluminum Crown Metal Company, and the metal itself combines 

 strength and lightness with elegance of appearance and general utility. 

 The bronze is of two kinds white and yellow the former being used 

 for cutlery and other table requisites where silver and plated goods 

 are now employed, for metallic fittings, and for every purpose where 

 a non-oxidizing, bright surface, with strength, is desired. The yellow 

 metal is adapted, and is used for articles and for details of machinery 

 where gun-metal and other alloys are now employed. It is said to 

 stand well in engine-bearings, and to give satisfactory results when 

 used in screw-propellers. The bronze is made in five qualities, and 

 each quality is made hard or soft as may be required. 



Silveroid, a metal introduced to public notice early in 1884, is an 

 alloy of copper and nickel adjusted with zinc, tin, or lead, in various 

 proportions, according to the purpose for which it is intended ; but 

 the secret of success in the manufacture is said to lie in a special 

 method of treatment at a certain point in the process. This alloy is 

 a metal of great whiteness, brilliancy, closeness of grain, and tensile 

 strength. 



Cobalt -bronze has been introduced since silveroid, by the same 

 manufacturers, Messrs. Henry Wiggin & Co., who produced that 

 metal. It is whiter and slightly more expensive than silveroid, and is 

 interesting as containing small quantities of cobalt, with the most de- 

 sirable qualities of that metal, particularly its malleability. It is manu- 



