STEEL HARDENING METALS. 



BY JOSEPH HYDE PRATT. 



(Joseph ITj'do Pratt, ponlogist and consulting mining (^nginocr; born Hartford, Conn., 

 Fibruary 3, 1S70; graduated from th(> Shcflicld .scientific sduxil of Yalf university; 

 instructor in mineralogy at "^'ale and later at the University of North Carolina; 

 state geologist of North Carolina 1S07-99; assistant geologist of the United States 

 geological survey since 1900. Author of about 125 monograph.s and other articles 

 on mineralogy and geology mostly contributed to scientific periodicals.] 



Chrome ore, or chromite, which contains the metal 

 chromium, was the first of the minerals containing any of 

 the steel hardening metals to l^e mined in the United States 

 for commercial pm'poses. The discovery of chrome ore in 

 this country was made about 1820 by Isaac Tyson, jr., at 

 Bare Hills, Md., 7 miles north of Baltimore, but the deposit, 

 being scanty and poor, was soon abandoned. He afterwards 

 found the mineral at Soldiers Delight, about 15 miles north- 

 west of Baltimore. In 1827 his attention was attracted by 

 the appearance in the market place of Baltimore of a man 

 from back in the country who had in his wagon several lumps 

 of a heavy black mineral wdiich he was using to keep a barrel 

 from rolling about in his cart. Upon testing these lumps, 

 Mr. Tyson found the mineral to be chromite and learned 

 that it was from Harford count}^, about 27 miles from Balti- 

 more. 



This was the beginning of chrome mining in this coun- 

 try and of the chrome industrj^ of the Tysons, which w^as 

 later supplemented by manufacturing processes and has 

 continued down to the present time. In the next year, 1828, 

 chromite was discovered in Lancaster county, Pa., and the 

 control of this property was also obtained by ]\Ir. Tyson. It 

 was afterwards developed into the famous Wood mine, which 

 has produced about 95,000 tons of chromite. 



Chromite mining in Maryland and Pennsylvania contin- 

 ued for a great many years until many of the deposits or 

 pockets of chromite were worked out. About the time the 

 ore began to grow scarce in these states, it was discovered 



Vol. (J-13 



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