From a conversation I (H. D.) had with my grandmother, Ella Josselyn, in 1955:
Alice (Josselyn) Bliss, Edgar Josselyn's sister, kept the Josselyn family records (now in my possession). The grandfather's clock (also in my possession) was owned by Harford Morse and Lucy (Gay) Morse. Edgar's first cousin, the child of Lucy's brother, also named Lucy Gay, was a school teacher and lived with Edgar's grandmother when the grandmother died, inheriting the clock from her. She in turn left it to Edgar.
Note added 1987: This is not quite correct. Lucy G. M. Card, 1857-1929, was the person who left the clock to Edgar Josselyn. To be Edgar's first cousin, she would have had to be the granddaughter (not the niece) of Lucy (Gay) Morse, Harford's wife, who lived 1793-1873 according to the tombstone. The oldest child of Harford and Lucy, Lucy Gay Morse, was born in 1813 and married James Card in 1835, according to the Roxbury Vital Records and Abner Morse's book (where the name is misspelled "Bard"). This daughter of Harford and Lucy would have been 44 when her daughter Lucy G. M. Card was born in 1857. Lucy G. M. Card was only 16 when her grandmother died in 1873.
Note added 3 August 2004: The 1870 census shows that Lucy (Gay) Morse, age 67, was living with four of her children in Boston Ward 13, and that Lucy G. M. Card, age 13, was living with her parents in Boston Ward 14. Both had post office Boston Highlands. So they lived near one another in 1870, but not together as Ella Josselyn stated. The 1920 census confirms that Lucy G. M. Card was a school teacher.