LONDON — A sextant owned by the captain of the first ship to respond to distress calls from the Titanic is being offered at auction.

English auctioneers Henry Aldridge & Son estimates that Sir Arthur Rostron's sextant will fetch 70,000 pounds ($111,000) at the sale next Saturday.

The auctioneer said Rostron acquired the navigational device in 1883, and it has remained in the family ever since. The instrument "would certainly have been the instrument he used to navigate through the ice floes," the auctioneer quoted great-granddaughter Janet Rostron as saying.

Rostron captained his ship as it dashed to the last known location of Titanic. Arriving two hours after Titanic sank on the night of April 14-15, 1912, Carpathia managed to rescue 705 people. Two other ships that arrived later found no survivors.