I don't know if the J is for John or James, but:
1901 census Tunbridge Wells, Kent
97 Shaffers (?) Rd.
Luker, Frederick J. head 26 engine driver stationary b. Tunbridge Wells, Kent
Luker, Carrie wife 26 America, USA
Luker, Sidney son 4 America, USA
Luker, Ernest son 2 Tunbridge Wells, Kent
Luker, Grace dau 8/12 Tunbridge Wells, Kent
RG13/754 Folio 129 Page 68