One of my scams indeed! Info here:-
http://www.steamindex.com/people/cubitt.htm
Interestingly there is also a Thomas Cubitt who was a London master builder also from Norfolk
http://en.wikipedia.org/wiki/Thomas_Cubitt
Sounds a bit like the Digges family from Barham locally, three generations of little appreciated mathematicians and scientists who no-one round here has ever heard of!
Thomas is my favourite as he was brought up by John Dee after his father's death, one of my Elizabethan heroes as anyone who has the largest private library in London has to be O.K. (especially when you also have a scrying table also which I have viewed at the Museum of Science at Oxford). Picture of latter below:-