John Percy knew EVERYONE. And when he needed an answer he got it.  
Most of what he did was contemporary (mid 1800s). So he is not as  
useful as a source on the history of the iron industry. But he is  
also using almost exclusively first person reports, not secondary  
sources. The same is not true of many of the other 19th and early  
20th century books. Unfortunately, most of what has been done since  
relies heavily on secondary sources and tends to reuse earlier work,  
rather than doing original research. Reference for Percy is:

Percy, John
     1864               Metallurgy: The Art of Extracting Metals from  
Their Ores, and Adapting Them to Various Purposes of Manufacture:  
Iron and Steel. John Murray, Albemarle Street, London.

There is a 1980s reprint, but the quality of the drawings is nowhere  
near as good as the original. It would appear that a new reprint may  
be available soon. One of his other volumes came out as a paperback.

James Brothers, RPA
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