Peggy, I have been doing some more research with the Irish Birth Registers,unfortunately I cannot find Thomas John Kernaghan. I searched the registers from 1870 to 1875 and no Thomas John was registered in any year. The only likelyhood is in 1871 where there is a Thomas born in Newry but the only way out of ensuring it is the person you require is to apply for the certificate to the Public Records Office in Belfast [PRONI]. They have a web site if you want it. The reference is 1871 vol.11 page 811. Sorry I couldn't help any further.