I meant to add that if you look up John and Agnes's marriage at the Manx Museum, or on LDS film no.0106182 at Family History Centres worldwide (in the phone book under Church of Jesus Christ of Latter-Day Saints), or buy a copy from the Registry: www.gov.im/registries/general/civilregistry/ that will give you the fathers' names and occupations and other details, which are invaluable - especially with a name from England like Smith.
Sue