Hello Rootschatters
After finding 500+ Trees on Ancestry for John "Longitude" Harrison I decided to research this family for myself.
I find that if the family had money Wills help enormously in tracing families in the 1700s and early 1800s. John Harrison received a great deal of money for his invention so I looked for John Harrison's Will.
He died in 1776 and mentions only two children in his Will - his son William and a daughter called Elizabeth who married John Barton. According to the Will there are four grandchildren. William's children, John, Ann and Elizabeth and Elizabeth's son John Barton. I have found no later mention of William's daughter Elizabeth, only John and Ann are mentioned in William's Will.
2nd Generation John Harrison's children
When we get to William's Will (he died in 1815) he has one grandchild, Elizabeth Barton, the daughter of his late daughter Ann Barton who married John Barton of Pimlico. This John it appears was her cousin the son of her Aunt Elizabeth and John Barton Senior mentioned in John's Will of 1776. William states Elizabeth is 17 yrs old. When Elizabeth married into the Wright family the announcement stated her father was "of the Bank of England".
William also has a son John who was born in 1761. Obligingly, William notes that John's mother was his first wife Elizabeth Atkinson and Ann's mother was his second wife Susannah Hodgson.
William's third wife also Elizabeth (Overton) was still alive but no children by her are mentioned.
Due to the money William's father got for his development of the marine chronometer, the family is now quite well off. There is property in London. William's son John and his granddaughter Elizabeth inherit, with provision made for William's third wife.
Third Generation John Harrison's grandson John
John Harrison 1761 - 1842 did not stay in London but returned to Lincolnshire and then moved to Hull. When he died in 1842 the Hull Packet newspaper notes he is the grandson of John Harrison who invented the chronometer. He was aged 80 according to the New GRO Index.
John was not married when his father died in 1815 but in the 1820s he formed a relationship with Jane Fenwick the wife of Richard Fenwick. This was much later in life than one would expect and no doubt accounts for the confusion we see in the on-line trees. If John had any earlier liaisons he does not mention them.
However in his Will written in 1836 John is quite candid about his relationship with Jane Fenwick and notes that his marriage is "legal under the law of Scotland" i.e. Common Law. He even states that Jane's maiden name was Proctor. (Bonus!) He has three children from this common law relationship, Charlotte, John and Henrietta. John and Henrietta were born at Great Grimsby in 1828 and 1829. I have not been able to track down Charlotte but the other children are with their parents at Spring Street in Hull in the 1841 Census. Also in the household is Ann Fenwick aged 20. The children were all minors when the Will was written and he mentions Guardians for them. They each inherited a house in London.
4th Generation - John Harrison Great-Grandson John 1828 - 1894
After John died Jane Harrison als Fenwick remained in the house in Spring Street Hull with her children John and Henrietta. John became a Civil Engineer. Henrietta died unmarried in 1873 and Jane died in 1878 at the age of 83. John continued living in the same house, unmarried, until his death on 12 July 1894. The Probate Register names an Emma Thornton, spinster as being granted probate. This person may be related to John's sister Charlotte. I have not obtained John's Will.
So it appears there are no living direct male descendants of John Harrison. There may be some from William's granddaughter Elizabeth Barton or his son John's daughter Charlotte but no living descendants called Harrison can exist. There maybe descendants from John Harrison's siblings especially his brother James. When John 1761 - 1842 left a specific time-piece to his son John in his Will he mentions that James was involved in the construction of it.
I love it that William and his son John gave so much information in their Wills regarding who the mothers of their children were. And so candid about the irregular marriage. Not hiding behind an anonymous trust arrangement that would not be a public document. It's almost as if they knew people would be looking for them. I think one thing we can take from this is that no direct descendant of John "Longitude" Harrison emigrated to the USA or Canada.
All the genealogical information I have found comes from Ancestry (PCC Wills), Find My Past (Lincs PRs and Newspapers) and Family Search and a few Internet searches. I have no connection to John Harrison but I thought it would be fun to see what I could find out sitting at my computer in snowy Canada. Please feel free to review the information for yourselves and let me know your conclusions.
Venelow
Canada