Lewis Watson died in 1732 and around then the Brown family moved the short distance from Heddon to Throckley, where they lived for the next forty or so years.
However, he would have served his apprenticeship in the 1730s, perhaps with William Newton, for they were related through their connection to the Watsons or maybe with his father or his neighbour Richard Peck, and by the 1740s was gaining expertise in designing waggonways.
From around 1750 Brown worked as a viewer – the man with the technical expertise to develop a colliery and then to deal with the geological and water problems inevitable in a mine.
He was responsible for all the machinery, the waggonways and had to be a competent surveyor He was expected to provide financial advice to the owners and to recruit, manage and retain the workforce needed to operate the mine.
The decision to make Throckley a seasale colliery – producing coal for shipment by sea, particularly to London – justified the building of its first railway, opened in 1751.
His work was not just limited to the North East – in 1754, he was commissioned by the Duke of Hamilton to provide a waggonway underground at Bo'ness Colliery near Edinburgh.
The first Boulton and Watt engine in the Northumberland and Durham coalfield was erected at Byker Colliery in 1778 to assist with pumping, almost certainly commissioned by Brown.
In this work he was associated with notable engineers of the eighteenth century, such as John Smeaton, James Brindley and Abraham Darby and his clients included dukes and earls as well as lesser gentry.