Ongoing attempts were made to improve the quality of the main light. In 1842 a new rotating optic was installed: manufactured by Cookson & Co. of Newcastle, it combined dioptric lenses with mirrors and displayed a white flash every two minutes. This arrangement was replaced in 1857 by a large (first-order) 8-sided revolving catadioptric optic manufactured by Chance Brothers giving the light a range (in fine weather) of over . (The following year, the dioptric section of the old 1842 optic was refurbished and installed in South Bishop Lighthouse.) Further attempts at improvement were made in 1889, when the frequency of the flash was increased to once every minute from once every two.London Gazette, Issue 25957, Page 4017, 26 July 1889
