One Titanic price tag: Unique diagram of sunken liner used at official inquiry ...
Participants, which included upper class passengers, used pointers throughout to illustrate which part of the ship they were talking about.
The inquiry, led by John Charles Bigham, Baron Mersey of Toxteth, began on May 2, 1912, at the London Scottish Drill Hall, Westminster, and continued until July 3.
It heard testimony from 100 witnesses over 36 days, including surviving crew, White Star Line officials, officers of other vessels and maritime experts.
In total, more than 25,000 questions were asked of the witnesses - though the enquiry was later criticised for ignoring Third Class passengers.
After the inquiry was concluded, it is believed the map was rolled up and stored away before passing into private hands.
It is now being sold by a private collector at Henry Aldridge and Son Auctioneers in Devizes, Wiltshire .
Andrew Aldridge, the auctioneer, said: 'It is a magnificent and commanding piece, both visually and historically. Just the size itself is incredible.
The 63-year-old from Merseyside had no idea the box was property of captain Edward John Smith, who went down with the doomed vessel in April 1912. It sold at auction today after being spotted on the off-chance by eagle-eyed auctioneer.
The firm’s original premises in Whiteladies Gate.