Thanks very much for all that information Kingskerswell.

I’ve been looking into the Osbornes of Ballyharigan (several other spellings available), trying to unravel to ownership of the townland.
There are a couple of things I’m finding confusing at the moment. The first is that the candidate for my ancestor who is supposed to have owned 800 acres had lots of children including several sons, yet it is his cousin (once removed), William Osborne who owned the land by the time of the Griffith’s Valuation.
The other, and I’m hoping someone might know about this, is records I’ve found relating to a sale under the encumbered lands courts:
[Dublin Evening Mail, 25 7 1855]
In the court for the sale of encumbered estates in Ireland ... in the matter of the estate of William Osborne, Esq., owner and petitioner, and in the matter of the Estate of said William Osborne, and of Joseph Osborne, an infant, Owners; Exparte, John Bates, Petitioner .... pursuant to the orders made in these matters, bearing date respectively the 24th day of April 1854, and 8th day May, 1855, Mr. George Walters, Auctioneer, will on Wednesday, the 10th day of October, 1855, at his auction Mart, situate in the city of Londonderry, at the hour of 12 o’clock at noon on said day, set up and sell in five lots, as specified below, the townland of Ballyhargan, otherwise Ballycarrigan, situate in the barony of Kennaught and County of Londonderry, containing 775A 0R 18P statute measure, held in fee-simple, and producing an annual rental of £512 10z 0d sterling....[PRONI D120/53]
7 February Irish Encumbered Estates Court Rentals. Rental and particulars of the estate of the said parties. Parties: Estate of William Osborne, Esq., and Joseph Osborne, an infant, owners, John Bates, Esq., petitioner. Relates to Ballyharigan, otherwqise Ballycarrigan, Co. Londonderry.[Allnut’s Irish Land Schedule, 15 Feb 1856]
RESULT OF PUBLIC SALES: Showing the number of years purchase each lot has realieed (?) amount of purchase money, and name of purchaser ... William Osborne (late owner); Ballyhargan &c (includes Altmover, Termalin, Knockanalara and Mill Farm); for a total of £9820 ... William Osborne (purchaser). My understanding is that the encumbered estates court was set up to sell land belonging to families which had fallen into debt, and to use the money to pay back the creditor(s). According to the table in the Allnut’s Irish Land Schedule it looks as though land formerly belonging to William Osborne was sold, at public auction to ... William Osborne. Is it possible that it was the same William Osborne, or must it have been someone else – perhaps a cousin, or his son?
Why is a “Joseph Osborne, infant” being mentioned? How old (young) did you need to be to be described as an infant. Under 1, under 3, under 8?
And who was John Bates? Could he have been the man to whom money was owed?