Copy letter from Herbert Rix, to the G.C.G. Colliery Company, 3 Mileage Station, Westbourne Park Road, W 'Dear Sirs Receipt no 5279, Mch [March] 27 for £6-0-0. Can you explain how it is that we were charged at the rate of 20/- per ton in the above a/c [account] whereas from the inclosed invoice it would appear that the rate should have been 18/- per ton? Yours faithfully, Herbert Rix Asst Secy RS [Assistant Secretary, Royal Society]'. 24 October 1888