I've just discovered this thread.
James Beatty from Enniskillen was my GGGfather.
He was surveying the Manchester & Derby railway in 1840, the Norwich and Lowestoft lines in 1842. Don't know what he was doing in Leicester in 1841, but his occupation looks to me like ingenieur.
He was chief engineer for the Southampton & Dorchester railway from 1845.
We have a copy of his will at the family home, but I don't remember him leaving anything to any employees. In any case, by the time he was surveying the New Brunswick railway in 1852 his home was in Camden Town, London, where he probably had a different set of domestic servants.