Alexander Raby was an Ironmaster who gained local interest by leasing the Downside Mills in Cobham, on the River Mole, in 1770. At first Raby lived in the house adjoining the mill and converted the it for iron fabrication. By 1781, the site also included two workshops, a stable, the iron mill and two forges. By about 1798 the site also included a copper mill. He also owned a large estate at Cobham Park, which he sold in 1795 before his departure for South Wales.
Arriving in Wales with a quarter of a million pounds, Raby was described as "one of the best authorities of the iron trade in the eighteenth century". As well as mining for coal in the Llanelli region, he also built tramroads and assisted in setting up the first ever ironworks in the district. By the second decade of the nineteenth century however, coal and other metals had usurped iron in importance in the Llanelli region, and Raby seemed to be in tune with the changes in popular demand, becoming involved with the copper-smelting industry before transferring his interests to coal mining in 1817.
Raby also owned Coxes Lock, regarded industrially as the most significant mill on the River Wey, and an instantly recognisable landmark on the Wey Navigation. With the infamous third Earl of Portmore apparently unhappy at the inconvenience the 'Hackering Jack' hammer at the heart of the mill was causing (delivering a pulverising 45 blows a minute, such industriousness doesn't come quietly!), Raby's lease on the mill was not renewed in 1808 where it was eventually converted from an ironworks to a flour mill.