A letter dated April 10, 1912, written on board the RMS Titanic, at Tennants auctioneers in Leyburn, North Yorkshire, that is expected to fetch up to 20,000 an expert said. The letter was written on board the reputedly unsinkable liner on White Star Line RMS Titanic headed notepaper from passenger Miss Alice Lennox-Conyngham - who sailed on the first leg of the cruise, from Southampton to Cherbourg in France - to her nephew Master Alan C Duff, telling how the liner had narrowly avoided a collision even before it left Southampton.