Email from Terry P: Mark Slater (1851) joined his brother William as a labourer at the Carlton Ironworks in Stockton and appears to have married Isabel Beatrice Herdsman in Stockton in 1871. I say appears because the probate records don't quite add up to the man we know ! He left her £39-17-6d which, bizarrely, is exactly the amount his dad left his mum