1851 England Census image for the birthplace of Thomas and Robert Jones looks like Watford, Hertfordshire.

Source: IGI

parent John Jones, Mary Jones

name Thomas Jones
gender Male
baptism/christening date 05 May 1837
baptism/christening place Watford, Hertford, England
father's name John Jones
mother's name Mary Jones

and brother Robert Jones

parent John Jones, Mary

name Robert Jones
gender Male
baptism/christening date 02 Jun 1839
baptism/christening place ST. MARYS, WATFORD, HERTFORD, ENGLAND
father's name John Jones
mother's name Mary