sentences:  The Poynton Colleries were substantial, and the coal rights were held by the Warren family who leased them the Wrights and the Claytons.In 1826 the estate passed to George John Venables Vernon, 4th Lord Vernon who decided in 1832 to manage the mines himself.In 1856 it was estimated that there was a reserve of 15,163,027 tons which would supply 245,000 tons for 61 years.