Major bequests include Reverend Chauncy Hare Townshend's collection of 154 gems bequeathed in 1869, Lady Cory's 1951 gift of major diamond jewellery from the 18th and 19th centuries, and jewellery scholar Dame Joan Evans' 1977 gift of more than 800 jewels dating from the Middle Ages to the early 19th century.
Approximately how many gems in Reverend Chauncy Hare Townshend's collection was given to the museum?
154