I chanced on this site and question while researching the history of the company I work for. Davy Bros was founded in Sheffield in 1830. Originally specialising in steam engines and forging plant, the company went on to become a leading international contractor for steelplant equipment. David and Dennis Davy were the original proprietors. David was killed in an industrial accident in 1865. If you're still interested in this, please contact me. There is a lot of material in the Local History Library and archives here in Sheffield, though I haven't got far through it yet. There are also a couple of other Davy families in trade gazettes from the second half of the 19th C. If you search the web for "Davy Bros" you will find a number of references, particularly to the steam engines the firm built. One of them, the so-called "River Don Engine" of 1905 is still in working condition in a local museum.