The Napier family was prominent in the Tennessee Iron industry. The Napier Furnace was originally called the Buffalo Iron Works. In 1845, it began to be referred to as Napier Mines. Napier Furnace operated until after WWI.
The notes from Napier Furnace are RARE and generally lower grade.
The pages on Buffalo - Napier Furnace are from Tennessee Iron Furnace Trail - A Guide to Resources on the Western Highland Rim by the Middle Tennessee Center for Historic Preservation.