Source (Emerald Ancestors):
Record Type Civil Marriage
Date of Marriage 11 Jul 1846
Groom Name Jacob FINLAY
Bride Name Jane TOSH
Church Dunboe First Presbyterian Church
Parish Dunboe
Civil District Coleraine
County Londonderry
The actual marriage entry shows him to be aged 21, bachelor, farmer of Ballyhacket, son of William Finlay, weaver. A James Finlay witnessed the marriage.
This man is not a brother of my Jane Finlay because his father was called William - nor is it likely that he is a brother of her father, John Finlay, as he was born 33 years later than John.
There is a Jacob in Ballyhackett Magilligan, Parish of Dunboe, in the Griffiths Valuation - unusual name, so it could be this man or it could be that the Jacob in the GV is the uncle of this man.