 The graphite was also used in pencil-making, which in 1790 led to the founding of the Cumberland pencil industry based in Keswick.The mine closed in 1891 after new techniques meant that graphite no longer needed to be so pure, so the Borrowdale mine became uneconomic.Grey Knotts can be ascended from Seathwaite or Seatoller in Borrowdale or from the top of the Honister Pass.