1836 Brothers James Hartley and John Hartley, Junior left Chance and Hartley (which then became Chance Brothers and Co) and moved north to Sunderland to set up their own business. The reasons why Sunderland was chosen as the site for their new venture are unclear, but it may have been because other family members (uncles and cousins) were already established in the glass making industry there.
The Wear Glass Works was established there around 1836, trading as James Hartley and Co.
On 25 November 1838, James Hartley was granted a patent for Hartley's Patent Rolled Plate, manufactured by a new cast glass process, and the firm concentrated on this for the next fifty years.
1847 James Hartley introduced a rolled plate glass with obscured ribbed finish, which is often found glazed in the roofs of railway termini.
1880 Hartley's works continued to produce large quantities of rolled plate glass - see The Glass Trade of the North.