Robert Baron
born March–May 1860
  in Preston, Lancashire
died 9 December 1860
  in Preston, Lancashire

Harry Jack noticed an entry in Thomas Baron's diary that suggested that a second child had been born while the family were still in Lancashire: 'the other unnamed child seems to be referred to in his diary on 12th December 1860. He had worked to Lancaster on the 10th and was there all night. On the 11th he worked back to Preston. Then on the 12th there is an unusual entry: "Shead & Buring Child". His spelling wasn't good but this seems to say that he spent the day in Preston engine shed, and burying a child. The following day (13th) he was back at work, firing on "2 trips to L[iver]pool." The entry about the child is pretty stark, but I can't think what else it can mean.'

Further research turned up the following death certificate:
  When and where died: 9th December 1860, 3 Lodge Street.
  Robert Baron, 9 months.
  Son of Thomas Baron, Railway Engine Stoker.
  Cause of death: Hydrocephalus, Spina Bifida, Fits. Certified.
  Informant: X the mark of Jane Smith, present at the death. Residence: 3 Lodge Street, Preston.
  Registered: 10th December 1860.
  Thomas Green Junr, Deputy Registrar.