I have no idea really, but I'll bet he was some glad to get out of that place and have a life, after all those years!
Do you suppose he could have served his apprenticeship right there in the workhouse?
Here are the names of some books which I have accumulated. I do not have the books in my possession, but they are in some libraries. Perhaps you will find a clue in one of them, if no one else knows:
Longmate, Norman. The workhouse. London : Temple Smith, 1974. 320 p. ISBN: 0851170382
Webb, Cliff. London, Middlesex and Surrey workhouse records : a guide to their nature and location. Surrey : West Surrey Family History Society, [1998], c1999, rev. 20 p. ISSN: 0261-5673
Morrison, Kathryn. Workhouse : a study of poor-law buildings in England. Swindon : Royal Commission on the Historical Monuments of England, 1999. 255 p. ISBN 1873592361. Includes bibliographical references (p. 240-243) and index.
Marshall, J. D. The Old Poor Law, 1795-1834; prepared for the Economic History Society.
London, Macmillan, 1968.
Englander, David. Poverty and poor law reform in Britain : from Chadwick to Booth, 1834-1914.
London : Longman, 1998. 142 p. ISBN: 0582315549(pbk.)
Derek Fraser, ed. The New Poor Law in the nineteenth century. London : Macmillan, 1976. 218 p. ISBN: 0333166558