A*'. 



Mew Seeies 



Vol. LV, No. 1417 



Friday, Febeuaet 24, 1922 



Single Copies, 15 Cts. 

 Annual Stibsceiption, $6.00 



The Rockwell 



ness Tester 



The most convenient 

 apparatus for quickly de- 

 termining the hardness of 

 metal castings, tools, dies 

 and similar apparatus. 

 Tests can be made in ten 

 seconds and even less in 

 certain classes of work. 



The operation is on the 

 principle of impressing a 

 1/16" diameter steel ball 

 into the sample piece and 

 noting on the dial the 

 depth of the impression 

 produced. No microscope 

 nor separate depth gauge 

 is necessary. 



The instrument is portable, accurate, rugged and can be operated by 

 anyone without preliminary training. 



3839/2 Sc. Rockwell Hardness Tester $345.00 



Write for special bulletin which gives full details, stating at the same 

 time your requirements. 



IS5 I 

 PITTSBURGH BRANCH 

 3rd Ave., 18th — 19th St. '"^^^J*' 4048 Jenkins Arcade 



Washington, D, C. Display Room, Suite 601, Evening Star Building, 

 Pennsylvania Avenue and 11th Street. 



