William was born in Kettering, about 1785, and had five sons:
- Henry Smith (1815-1859)
- Nathaniel (1814-1897)
- William (1819-1895)
- Robert (1821-?)
- Charles (1822-?)
The Smith family, as befits their name, were all connected with engineering.
As a young machinist from Kettering, Henry went to Stamford in 1837 and set up in his own account in the Sheep Market.
Nathaniel and Robert joined Henry in the Stamford works. The full extent of their involvement is not fully clear.
Robert is notable for founding the works band.
Nathaniel, like other family members, was very active in the temperance movement. He later took over an iron foundry at Thrapston and founded his own engineering dynasty.
Almost nothing is known about the fourth brother, Charles, only that he was described in the 1851 Census as a machine maker.
William (Jnr) set up an engineering works in his home town of Kettering. By 1849 his works, in Sheep Street, had become known as the Royal Iron Works. Here William, and later his son James, produced an extensive catalogue of agricultural machinery. Many were prize-winners. Among them was a 12-row steerable horse hoe, which won an award at the Royal Agricultural Society’s show in 1865. William retired in 1885.
Eventually, Kettering Borough Council acquired the site and in 1904 the old works were demolished. A free public library, museum and art gallery were then built on the site. This building is now Kettering Library.