Harry, there are 2 trees on Ancestry which say that he married Mary Vernon in Liverpool in 1876. One tree says that he died in Australia, but no other details.

I have no way of knowing if it's true.

Here he is in 1871. I can't see him in 1881 or 1891.

1871
Liverpool, Dale St 22/46
21 Pall Mall

Name Age
Richard Hallowell 25
Sarah Hallowell 23
John W Hallowell 3
Sarah E Hallowell 1
John T Townsend 21
William W Townsend 24

JTT is a lodger, labourer b IOM

*************************
England & Wales, FreeBMD Marriage Index: 1837-1915
about John Thomas Townsend
Name: John Thomas Townsend
Date of Registration: Oct-Nov-Dec 1876
Registration district: Liverpool
Inferred County: Lancashire
Volume Number: 8b
Page Number: 131

*******************
England & Wales, FreeBMD Marriage Index: 1837-1915
about Mary Vernon
Name: Mary Vernon
Date of Registration: Oct-Nov-Dec 1876
Registration district: Liverpool
Inferred County: Lancashire
Volume Number: 8b
Page Number: 131

********************

Jean C